Featured Image: [Image of a person measuring a window frame with a measuring tape]**
Replacing windows can be a daunting task, but it’s important to get the right measurements before you start shopping. If your windows are not measured correctly, they will not fit properly and could cause air leaks or other problems. In this article, we will provide you with a step-by-step guide on how to measure for replacement windows.
Measuring the Width and Height
The first step is to measure the width and height of your window opening. To do this, you will need a measuring tape. Start by measuring the width of the opening, from the inside edge of the frame on one side to the inside edge of the frame on the other side. Next, measure the height of the opening, from the top of the frame to the bottom of the frame. Be sure to measure the opening itself, not the window sash.
Measuring the Depth
Once you have measured the width and height of the opening, you need to measure the depth of the frame. To do this, you will need to use a depth gauge. Insert the depth gauge into the opening and measure the distance from the inside edge of the frame to the outside edge of the frame. Be sure to measure the depth at several different points around the opening to ensure that it is consistent.
Determine the Dimensions of Your Existing Windows
Height Measurement
To measure the height, use a measuring tape and extend it from the top of the window frame to the bottom of the frame. Make sure to measure from the inside surface of the frame, not the outside. Record this measurement as “height.”
Width Measurement
For the width measurement, place the measuring tape horizontally across the window frame from side to side. Again, measure from the inside surface of the frame. Note this measurement as “width.”
h4>Measuring Irregularly Shaped Windows
Irregularly shaped windows, such as arches or circles, require a bit more precision. Divide the window into smaller sections and measure each section individually. Note the dimensions of each section and add them together to get the overall height and width.
Sill Projection and Window Depth
The sill projection is the distance that the window sill protrudes from the exterior wall. Measure this distance from the furthest point of the sill to the outside surface of the wall.
For the window depth, measure from the inside surface of the interior frame to the exterior surface of the exterior frame.
This table summarizes the measurements you need to take:
| Measurement | How to Measure |
|---|---|
| Height | Top to bottom of the interior frame |
| Width | Side to side of the interior frame |
| Sill Projection | From sill to exterior wall surface |
| Window Depth | From interior frame surface to exterior frame surface |
Calculate the Rough Opening Dimensions
The rough opening (RO) is the hole in your wall where the window will be installed. To measure the RO, you’ll need to measure the width and height of the opening, as well as the depth of the opening from the interior to the exterior.
To measure the width, measure the distance between the inside edges of the framing on both the left and right sides of the opening. To measure the height, measure the distance between the inside edges of the framing on the top and bottom of the opening.
To measure the depth, place a measuring tape on the interior side of the opening and extend it to the exterior side of the opening. Measure the distance from the interior edge of the framing to the exterior edge of the framing. This will give you the depth of the opening.
Once you have the RO dimensions, you can use them to order your replacement windows. Keep in mind that the RO dimensions are typically slightly larger than the actual window dimensions, so be sure to order windows that are slightly smaller than the RO.
Determining the RO Dimensions for Picture Windows
Picture windows are fixed windows that do not open, so they are typically installed in a larger RO than other types of windows. To determine the RO dimensions for a picture window, measure the width and height of the opening, as well as the depth of the opening from the interior to the exterior.
Once you have the RO dimensions, you can use the following formula to calculate the actual window dimensions:
“`
Actual Window Width = RO Width – 2 inches
Actual Window Height = RO Height – 2 inches
“`
The 2-inch deduction is to account for the overlap of the window frame on the interior and exterior of the wall.
| Measurement | Formula |
|---|---|
| Actual Window Width | RO Width – 2 inches |
| Actual Window Height | RO Height – 2 inches |
Measure the Interior and Exterior Width
To ensure an accurate fit for your replacement windows, it’s crucial to measure both the interior and exterior widths. Here’s how to do it:
Interior Width
Measure from the inside edge of the left jamb to the inside edge of the right jamb. Record this measurement in inches to the nearest 1/8 inch.
**Tip:** Refer to the following table for a visual guide:
| Measurement Type | Description |
|---|---|
| Rough Opening Width | Interior width of the window frame before trim |
| Window Unit Width | Exterior width of the replacement window frame |
Exterior Width
Measure from the outside edge of the left brickmold to the outside edge of the right brickmold. Round this measurement up to the nearest 1/2 inch for a snug fit.
**Note:** Brickmold is the trim around the exterior of the window frame.
By following these instructions, you’ll gather accurate measurements for your replacement windows, ensuring a seamless installation and a snug fit that will enhance energy efficiency and home comfort.
Calculate the Head and Sill Heights
Measuring the head and sill heights accurately is crucial for ensuring a proper fit for your replacement windows. Follow these steps:
1. Measure the Existing Window
Remove any window treatments or hardware that may obstruct your measurements. Using a tape measure, measure the vertical distance from the top of the existing window frame to the bottom of the header above the window. Record this measurement as the “head height.”
2. Locate the Sill Height
Next, measure from the bottom of the existing window frame to the top of the sill below the window. This provides the “sill height” measurement.
3. Subtract the Frame Thickness
To determine the actual head and sill heights for the replacement window, you need to subtract the thickness of the existing window frame. Measure the thickness of the frame by measuring from the outer edge of the window frame to the edge that sits against the wall. Subtract this measurement from both the head and sill height measurements.
4. Consider Sill Drainage
In areas with significant rainfall, it’s crucial to ensure that your replacement windows have adequate sill drainage. This involves creating a slight slope in the sill towards the exterior of the home to prevent water from pooling. Aim for a slope of at least 1/8 inch per foot, which equates to 0.625 inches for every 5 feet of sill length.
Here’s a table for easy reference:
| Measurement | Formula |
|---|---|
| Head Height | Existing Head Height – Frame Thickness |
| Sill Height | Existing Sill Height – Frame Thickness |
| Sill Slope | 0.625 inches per 5 feet of sill length |
Account for the Casing Width
Every window has casing, which is the decorative trim surrounding the frame. When measuring for replacement windows, it’s crucial to consider the casing width. Here’s how to measure the casing width accurately:
Step 1: Measure the Interior Casing
Start by measuring the width of the casing on the inside of the window frame. Use a measuring tape and hold it firmly against the edge of the casing. Record the measurement.
Step 2: Measure the Exterior Casing
Next, measure the width of the casing on the outside of the window frame. Follow the same procedure as for the interior casing, holding the measuring tape against the edge of the casing. Note down the measurement.
Step 3: Add the Interior and Exterior Widths
Once you have the interior and exterior casing widths, add them together. This will give you the total casing width.
Step 4: Multiply by Two
Finally, multiply the total casing width by two. This is because there’s casing on both the left and right sides of the window.
Step 5: Subtract the Casing Width from the Window Opening Width
The final step is to subtract the total casing width (from Step 4) from the window opening width. This will give you the width of the replacement window that you need to order.
| Casing Width Measurement Guide | |
| Step 1: Interior Casing Width | Measure and record the width of the casing on the inside of the window frame. |
| Step 2: Exterior Casing Width | Measure and record the width of the casing on the outside of the window frame. |
| Step 3: Add the Widths Together | Add the interior and exterior casing widths to get the total casing width. |
| Step 4: Multiply by Two | Multiply the total casing width by two to account for both sides of the window. |
| Step 5: Subtract Casing Width from Opening Width | Subtract the total casing width from the window opening width to determine the replacement window width. |
Check for Squareness and Level
Ensuring the squareness and level of your window opening is crucial for proper window installation. Follow these steps:
Check for Squareness
- Measure the diagonal distances between the opposite corners of the opening.
- If the measurements are not equal, the opening is not square.
- Adjust the framing or use shims to square the opening.
Check for Level
- Place a level on the sill and check for level both horizontally and vertically.
- If the sill is not level, adjust the framing accordingly.
- Use a level to check the jambs (sides) of the opening for verticality.
- Adjust the framing or use shims to level the jambs if necessary.
- If the sill or jambs are not level, the window will not fit properly and may cause operational issues.
| Measurement | Purpose |
|---|---|
| Diagonal measurements | Check for squareness |
| Level on sill | Check for horizontal level |
| Level on jambs | Check for vertical level |
Measure for Architectural Features
When measuring for replacement windows, it’s important to account for any architectural features that may affect the fit of the new windows. These features can include bay windows, bow windows, casement windows, double-hung windows, sliding windows, and transom windows.
Bay Windows
Bay windows are a type of window that projects outward from the house, creating a bay or alcove. To measure for a replacement bay window, you will need to measure the width of the bay, the height of the bay, and the depth of the bay.
Bow Windows
Bow windows are similar to bay windows, but they have a curved shape. To measure for a replacement bow window, you will need to measure the width of the bow, the height of the bow, and the depth of the bow.
Casement Windows
Casement windows are windows that are attached to the frame by hinges on one side. To measure for a replacement casement window, you will need to measure the width of the window, the height of the window, and the depth of the window.
Double-hung Windows
Double-hung windows are windows that have two sashes that slide up and down. To measure for a replacement double-hung window, you will need to measure the width of the window, the height of the window, and the depth of the window.
Sliding Windows
Sliding windows are windows that have two sashes that slide horizontally. To measure for a replacement sliding window, you will need to measure the width of the window, the height of the window, and the depth of the window.
Transom Windows
Transom windows are windows that are located above another window or door. To measure for a replacement transom window, you will need to measure the width of the window, the height of the window, and the depth of the window.
Consider the Type of Replacement Window
Choosing the type of replacement window will determine what measurements you need to take. There are various types of windows available, including:
Casement Windows
These windows are hinged on one side and open outward with a crank handle. They require measuring the width, height, and depth of the opening, as well as the inside and outside trim.
Double-Hung Windows
Double-hung windows have two sashes that can be raised and lowered independently. You need to measure the width, height, and depth of the opening, as well as the height and width of each sash.
Sliding Windows
Sliding windows have two sashes that slide horizontally past each other. Measure the width, height, and thickness of the frame, as well as the width and height of each sash.
Bay Windows
Bay windows are composed of three or more windows that form an angled bay. Measure the width and height of each window and the overall width and height of the bay opening.
Picture Windows
Picture windows are fixed panes that do not open. You only need to measure the width, height, and depth of the opening.
Other Considerations
In addition to the basic measurements, consider the following:
- Frame style: Measure the width and thickness of the frame.
- Glazing: The thickness of the glass will also affect the measurements.
- Features: Any special features, such as grilles or screens, may require additional measurements.
- Installation method: Whether the windows will be installed inside or outside the frame will impact the measurements.
To ensure accurate measurements, it’s recommended to hire a professional window installer. They can take precise measurements and provide the best advice on the type of windows and installation method for your home.
| Window Type | Measurements Needed |
|---|---|
| Casement | Width, height, depth, inside/outside trim |
| Double-Hung | Width, height, depth, sash height/width |
| Sliding | Width, height, frame thickness, sash height/width |
| Bay | Width/height of each window, overall width/height |
| Picture | Width, height, depth |
Consult with a Window Professional
Step 1: Do Your Research
* Gather information about different window types, materials, and manufacturers.
* Explore online reviews, visit showrooms, and attend home improvement events.
Step 2: Determine Your Needs
* Consider factors such as energy efficiency, natural light, ventilation, and noise reduction.
* Consult with a professional to discuss specific requirements for your home and climate.
Step 3: Measure Your Existing Windows
* Use a tape measure to determine the width, height, and depth of your current windows.
* Measure the distance between the window frame and the outer edge of the wall.
Step 4: Rough Opening Measurement (for new construction or renovations)
* Measure the width and height of the opening where the new window will be installed.
* Ensure that the rough opening is the correct size for the chosen window style and size.
Step 5: Review Manufacturer’s Specifications
* Obtain the manufacturer’s specifications for the window you have selected.
* Check the designated clearance measurements and ensure they align with your existing or planned rough opening.
Step 6: Consider Trim and Molding
* Determine the thickness and width of any existing or desired trim and molding.
* Account for these measurements when calculating the overall size of the replacement window.
Step 7: Allow for Flashing
* Calculate the amount of flashing material needed to seal the window against moisture penetration.
* Typically, a width of 4-6 inches is sufficient for flashing on all sides of the window.
Step 8: Verify Measurements
* Double-check all measurements to ensure accuracy.
* It’s advisable to have a professional window installer verify your measurements before ordering the replacement windows.
Step 9: Professional Assistance
* Hiring a qualified window professional is highly recommended for precise measurements.
* They can provide expert advice, identify potential issues, and ensure a proper fit and installation.
| Measurement | Considerations |
|---|---|
| Width | Include trim and molding, if applicable. |
| Height | Include the distance between the window frame and the wall. |
| Depth | Determine the amount of space available for the window and flashing. |
| Rough Opening | Ensure the opening is the correct size for the chosen window. |
Use Precision Tools for Accuracy
Measuring for replacement windows requires precision to ensure a perfect fit. Here are some tips to help you get accurate measurements:
1. Choose the Right Tools
Use measuring tapes with a minimum of 16-foot capacity and laser levels for maximum accuracy. Avoid using rulers or yard sticks.
2. Measure the Height
Measure from the top of the existing window to the bottom, including any trim or molding.
3. Measure the Width
Measure from the left side of the existing window to the right side, again including any trim or molding.
4. Measure the Rough Opening
This is the actual opening in the wall where your new window will be installed. Measure from one side of the opening to the other, then from the top of the opening to the bottom.
5. Determine the Sill Height
Measure from the bottom of the rough opening to the ground or floor.
6. Measure the Jamb Depth
This is the distance from the back of the rough opening to the interior finished wall. Measure from the back of the rough opening to the drywall or plaster.
7. Measure the Reveal Width
This is the distance from the edge of the finished wall to the edge of the existing window frame. Measure from the outside edge of the drywall or plaster to the outside edge of the frame.
8. Check for Square
Use a laser level to ensure that your measurements are square. Measure from the top left corner to the bottom right corner, and then from the bottom left corner to the top right corner. The measurements should be the same.
9. Measure the Existing Window
Measure the width, height, and thickness of the existing window. This will help you determine the size of the replacement window you need.
10. Table of Measurement Details
To help you keep track of your measurements, use the following table:
| Measurement | Value |
|---|---|
| Height | [Height Value] |
| Width | [Width Value] |
| Rough Opening Height | [Rough Opening Height Value] |
| Rough Opening Width | [Rough Opening Width Value] |
| Sill Height | [Sill Height Value] |
| Jamb Depth | [Jamb Depth Value] |
| Reveal Width | [Reveal Width Value] |
| Existing Window Width | [Existing Window Width Value] |
| Existing Window Height | [Existing Window Height Value] |
| Existing Window Thickness | [Existing Window Thickness Value] |
How To Measure For Replacement Windows
Step 1: Gather Your Tools
You will need a measuring tape, a pencil, and a piece of paper.
Step 2: Identify the Type of Window
There are three main types of windows: single-hung, double-hung, and casement. Single-hung windows have one sash that moves up and down, while double-hung windows have two sashes that move up and down. Casement windows have a crank that opens the sash outward.
Step 3: Measure the Width
Measure the width of the window from the outside edge of the frame, across the opening, to the outside edge of the frame on the other side.
Step 4: Measure the Height
Measure the height of the window from the bottom of the frame, up the side of the opening, to the top of the frame.
Step 5: Measure the Depth
Measure the depth of the window from the inside of the frame to the outside of the frame.
Step 6: Check Your Measurements
Once you have measured the window, double-check your measurements to make sure they are accurate.
Step 7: Order Your Windows
Once you have your measurements, you can order your replacement windows. Be sure to provide the manufacturer with the exact measurements of your windows, including the width, height, and depth.
People Also Ask About How To Measure For Replacement Windows
How do I measure for a sliding window?
To measure for a sliding window, you will need to measure the width and height of the opening. The width is measured from the inside of the frame on one side to the inside of the frame on the other side. The height is measured from the bottom of the frame to the top of the frame.
How do I measure for a bay window?
To measure for a bay window, you will need to measure the width and height of each section of the window. The width is measured from the outside of the frame on one side to the outside of the frame on the other side. The height is measured from the bottom of the frame to the top of the frame.
How do I measure for a picture window?
To measure for a picture window, you will need to measure the width and height of the opening. The width is measured from the inside of the frame on one side to the inside of the frame on the other side. The height is measured from the bottom of the frame to the top of the frame.
