How to Measure for Curtains: A Step-by-Step Guide
The difference between curtains that look custom and curtains that look like an afterthought comes down to one thing: measurement. In our ten years of crafting made-to-measure window treatments for over twelve thousand homes, we’ve seen the same mistakes again and again—curtains that float two inches above the floor, panels that barely cover the window frame, and rods mounted so low they make eight-foot ceilings feel like a basement.
The good news? Measuring for curtains is straightforward once you know what to do. This guide walks you through every step, from choosing your mounting style to calculating the perfect fullness. Whether you’re ordering custom linen drapes for a living room or blackout panels for a bedroom, accurate measurements ensure your curtains fit flawlessly the first time.
If you prefer a visual reference, our detailed curtain measuring guide includes diagrams and a downloadable worksheet. For Roman shades, we have a separate shades measuring guide with its own specific steps.
What You’ll Need
Before you start, gather these tools:
- Metal measuring tape (cloth tapes stretch and give inaccurate readings)
- Smart Laser Distance Measure Tool (optional—measures windows in 60 seconds with professional-grade accuracy up to 164 ft)
- Step ladder for reaching above the window frame
- Notepad and pencil for recording measurements
- Level (optional, for ensuring rod placement is straight)
- A second person (optional but helpful for wide windows)
Time required: 15–20 minutes with a tape measure. If you’re using the Smart Laser Distance Measure Tool, you can measure a standard window in under 60 seconds with professional-grade accuracy.
Step 1: Choose Your Mounting Style
The first decision affects every measurement that follows. You have two options:
Outside Mount (recommended for most installations)
The rod or track sits on the wall above and outside the window frame. This is the most popular choice because it makes windows look larger and ceilings feel taller. For outside mount, you’ll measure the wall space you want the curtains to cover—not just the window itself.
Inside Mount
The rod or track fits inside the window recess. This creates a cleaner, built-in look but requires precise measurements since there’s no room for error. Inside mount works best when you have decorative molding around the window or limited wall space.
Pro tip from our installation team: For standard rooms, we recommend outside mount in ninety percent of cases. It gives you more flexibility with curtain length and width, and the visual effect is dramatically better.
Step 2: Measure the Width
For Outside Mount
Measure the width of the area you want the curtains to cover. A good rule of thumb is to extend 6–15 inches beyond each side of the window frame. This ensures the curtains fully cover the window when closed and stack neatly to the sides when open.
Formula: Window width + 12–30 inches total (6–15 inches per side)
For example, if your window is 50 inches wide, your rod should be 68–80 inches wide.
For Inside Mount
Measure the exact inside width of the window recess at the top, middle, and bottom. Use the narrowest measurement to ensure the rod or track will fit. Deduct ¼ inch from this number to allow smooth operation.
Formula: Narrowest inside width − ¼ inch
Step 3: Measure the Height
For Outside Mount
Decide where you want the rod positioned. For the most flattering look, mount the rod 4–6 inches above the window frame—or halfway between the window top and the ceiling, whichever looks better in your space.
Measure from the rod position down to where you want the curtains to end:
- Float: ½ inch above the floor (clean, modern, easy to vacuum)
- Kiss: Just touching the floor (tailored, professional look)
- Puddle: 1–3 inches pooling on the floor (romantic, formal)
Formula: Rod position to floor − desired clearance
For Inside Mount
Measure the exact inside height of the window recess on the left, center, and right. Use the shortest measurement. Deduct ¼ inch so the curtains don’t drag on the sill.
Formula: Shortest inside height − ¼ inch
Pro tip: Always measure twice. We’ve seen homeowners order curtains based on a single rushed measurement, only to discover their floors aren’t perfectly level or their window frames aren’t perfectly square.
Step 4: Calculate Curtain Fullness
This is where many people go wrong. Curtain width isn’t the same as rod width—you need extra fabric for proper gathering.
The industry standard is 2× fullness. This means your total curtain width should be roughly twice the width of your rod.
| Rod Width | Total Curtain Width (2×) | Number of Panels |
|---|---|---|
| 48 inches | 96 inches | 2 panels (48” each) |
| 60 inches | 120 inches | 2 panels (60” each) |
| 72 inches | 144 inches | 2–3 panels |
| 96 inches | 192 inches | 3–4 panels |
For a fuller, more luxurious effect, lightweight fabrics like sheer linen perform best with 2× fullness. This fullness ratio also pairs perfectly with specialty header styles such as ripple fold, delivering a sleek, tailored finish. Heavy-weight materials including velvet and chenille achieve the most elegant drape at 2× fullness. For minimalist and budget-friendly installations, 1.5× fullness is a functional, streamlined option.
You can use our Smart Measurement Tool to calculate fullness automatically—just enter your window dimensions and desired style, and it generates a complete measurement report with recommended panel sizes. For the most accurate window dimensions in the first place, our Smart Laser Distance Measure Tool measures distances in 60 seconds with five precision modes and a 164-foot range—eliminating the reading errors that happen with traditional tape measures.
Step 5: Determine Rod or Track Placement
Where you place the hardware matters as much as the curtain dimensions.
Height: As mentioned, 6-10 inches above the window frame is standard. For rooms with ceilings higher than 9 feet, consider mounting halfway between the window and ceiling to maximize vertical impact.
Depth: Ensure your rod or track extends far enough from the wall to clear any trim, blinds, or shutters. Standard brackets project 3–4 inches from the wall, but deeper projections are available if needed.
Width extension: For outside mount, the rod should extend 6-15 inches beyond each side of the frame. This allows the curtains to stack back without blocking the window glass when open.
If you’re unsure about placement, our curtain measuring guide includes a visual placement chart for every ceiling height from 8 to 14 feet.
Step 6: Record and Double-Check
Write down every measurement in this format:
Window: [Room name]
Mount type: Outside / Inside
Rod width: ___ inches
Curtain width needed: ___ inches (___ panels at ___ inches each)
Curtain length（height）needed: ___ inches
Fullness ratio: ___×
Desired finish: Float / Kiss / PuddleDouble-check everything. Measure a second time, especially if you’re ordering custom curtains. Unlike ready-made panels that you can return to a store, custom orders are made to your exact specifications.
Common Mistakes to Avoid
Measuring only once. Window frames are rarely perfectly square. Measure width at three heights and height at three widths, then use the smallest numbers.
Forgetting about fullness. Ordering curtains the same width as your rod results in flat, stretched panels that look cheap. Always calculate your desired fullness.
Ignoring the floor. If you have carpet, measure to the subfloor or account for carpet height. A curtain that kisses hardwood may float on thick carpet.
Mixing up width and height. It sounds obvious, but in our experience, it happens more often than you’d think. Label every measurement clearly.
Not accounting for hardware. If you’re layering sheers behind drapes, you need a double rod with enough projection to accommodate both layers without tangling.
When to Call a Professional
Some situations warrant professional measurement:
- Ceilings higher than 10 feet—ladder safety and precise height measurement become challenging
- Bay windows or corner windows—angled walls require specialized techniques
- Windows wider than 96 inches—accurate width measurement across a large span is difficult alone
- Uneven floors or ceilings—older homes often have subtle slopes that affect curtain hang
At Freshine, we offer complimentary measurement review with every order. Upload a photo of your window along with your measurements, and our team verifies everything before production begins. For complex installations, we can connect you with a local measurement professional.
How Freshine Simplifies the Process
Accurate measurements are the foundation of custom curtains that fit perfectly. We’ve built three resources to make sure you get it right:
1. Smart Measurement Tool Our online measurement tool walks you through each step with interactive diagrams. Enter your window dimensions, select your mounting style and desired finish, and it calculates exact panel sizes—including fullness recommendations based on your fabric choice.
2. Smart Laser Distance Measure Tool For homeowners who want professional-level accuracy without hiring a professional, our Smart Laser Distance Measure Tool transforms measurement from a two-person chore into a 60-second solo task. It features five precision modes, a 164-foot range, and eliminates the parallax errors and tape-sag issues that cause inaccurate readings. Simply point, click, and record—especially useful for high ceilings, wide windows, and hard-to-reach areas where a ladder and tape measure become cumbersome.
3. Detailed Measurement Guides For curtains, our complete measuring guide covers standard windows, extra-long installations, and specialty shapes. If you’re also considering Roman shades, our shades measuring guide explains the differences in measurement technique between curtains and shades.
4. Product Page Integration Every curtain product page on Freshine includes a “Need Help Measuring?” section with quick-reference charts and a direct link to our measurement resources. You’ll also find the Smart Laser Distance Measure Tool available right alongside your curtain selection—so you can add professional-grade measurement equipment to your order in one click.
And because every Freshine curtain is made to order, you’re never limited to standard sizes. Whether you need 84-inch panels for a city apartment or 168-inch drapes for a great room with 14-foot ceilings, we craft each order to your exact specifications.
Frequently Asked Questions
How do I measure for curtains on a bay window?
Bay windows require individual measurements for each section. Measure each panel’s width and height separately, and note the angles where sections meet. Our curtain measuring guide includes a dedicated bay window section with diagrams. For complex bay configurations, we recommend our complimentary measurement review service.
Should I measure to the floor or to the bottom of the window frame?
For floor-length curtains—which are standard for most rooms—measure to the floor. For windows above a radiator, counter, or piece of furniture, measure to the windowsill or 1–2 inches below the obstruction. The key is consistency: never measure to different points on different windows in the same room.
What if my window isn’t perfectly square?
Very few windows are. Measure width at the top, middle, and bottom; measure height at the left, center, and right. For inside mount, use the smallest width and shortest height. For outside mount, use the largest width and longest height to ensure full coverage. Our Smart Measurement Tool flags common irregularities and adjusts recommendations accordingly.
How much wider than the window should curtains be?
For outside mount, the rod should be 12-30 inches wider than the window (6-15 inches per side). The curtains themselves should be roughly 2× the rod width for proper fullness. For example, a 60-inch window needs a 72–90 inch rod and 120-150 inches of total curtain fabric.
Can I measure for curtains by myself?
Yes, for standard windows up to about 60 inches wide. Use a metal tape measure, work from left to right in a consistent pattern, and write down each measurement immediately. For windows wider than 72 inches or ceilings higher than 9 feet, a second person makes the process significantly easier and more accurate. If you’re ordering custom curtains, the few extra minutes of careful measurement are always worth it.
Ready to Order?
With your measurements in hand, you’re ready to explore custom curtains that fit your windows perfectly. Browse our complete collection, order fabric swatches to see colors and textures in your own space, or reach out to our team if you have questions about your measurements.
Have your numbers ready? Shop all custom curtains and enter your exact dimensions at checkout.