Floor Plan Square Footage Calculator
Upload the floor plan and get its total square footage, or type each room's dimensions below and add them up. Your first plan is free, no signup required.
JPG · PNG · PDF · HEIC
Or add up the room dimensions
Already have the numbers written on the plan? Enter each room's length and width and the total updates as you type.
Room-by-room totals use interior dimensions, so they usually land a little under the exterior number on an appraisal. See why below.
How to calculate square footage from a floor plan
There are two ways to get square footage from a floor plan. If the plan is labeled with room dimensions, multiply and add. If it is not, or you want the number an appraiser would report, measure the drawing itself. This floor plan square footage calculator does both.
Method 1: Add up the labeled room dimensions
- Find the length and width printed in each room. On most plans they read like 12'6" x 14'0".
- Convert inches to a decimal (6 inches is 0.5 feet), or switch the calculator above to inches and enter everything in inches.
- Enter each room as its own row. Include closets, halls, and bathrooms; skip the garage and anything below grade.
- Read the total. For an L-shaped room, enter it as two rectangles.
This is quick and works for planning, flooring, and a rough check on a listing. Its weakness is that it measures the inside of each room, so walls, odd corners, and any space you forgot never make it into the total.
Method 2: Upload the plan and measure it
- Upload the floor plan as a PDF, JPG, PNG, or HEIC. Listing screenshots and phone photos of a printed plan work too.
- Set the scale by clicking both ends of one dimension you know. A labeled wall is ideal. If nothing is labeled, a standard door (36 inches) or bathtub (60 inches) does the job.
- Trace the outline of each floor, or click individual rooms. The tool calculates the area from the drawing at that scale.
- Read the total, then download a labeled PDF with every measurement on it if you need to share it.
Because you trace the real outline, this method handles angled walls, bays, and open layouts that room math cannot, and tracing the exterior gives you the same kind of number an appraiser reports. The full walkthrough is in how to calculate square footage from a floor plan.
What to include in floor plan square footage
Square footage means finished, above-grade living space. Rooms you live in count. Garages, porches, and unfinished space do not. Basements are measured but kept on their own line. The table covers the cases that cause most disagreements.
| Space | Counts? | Why |
|---|---|---|
| Bedrooms, living areas, kitchen, dining | Yes | Finished, above-grade living space is the core of the total. |
| Bathrooms, closets, hallways, pantries | Yes | Every finished space on a finished floor counts, however small. |
| Stairs | Yes | Counted once, with the floor they descend from. |
| Interior walls | Yes, if measured from outside | Appraisers measure the exterior, so walls are inside the number. Room-by-room totals from interior dimensions leave them out. |
| Finished attic or half story | Only if it qualifies | Needs a 7-foot ceiling over at least half the area and a permanent stair. Only the part over 5 feet counts. |
| Garage | No | Never living area, even when attached, finished, and heated. |
| Finished basement | Separate line | Measured, but reported as below-grade area, not added to the above-grade total. |
| Unfinished basement or attic | No | Unfinished space is not living area anywhere in the house. |
| Covered porch, deck, patio, balcony | No | Not enclosed finished space. |
| Sunroom or enclosed porch | Only if finished like the house | Must be finished and heated to the same standard as the rest of the home. |
The longer version, with the edge cases, is in what counts as square footage in a house.
Why your total may not match the listing
Three different people can measure the same house and report three different numbers, and none of them are lying. They are measuring different things.
Listings and Zillow often quote a "total" that folds in a finished basement, a bonus room over the garage, or whatever the county assessor had on file. Listing square footage is rarely re-measured.
Appraisers follow ANSI Z765. They measure the outside of the house, count only finished above-grade space, and report the basement separately. That number is usually the smallest of the three, and it is the one a lender uses. How appraisers calculate square footage walks through it.
Room-by-room math, like the calculator above, uses interior dimensions. It skips wall thickness entirely, which is why it tends to come in a little under the appraisal. Whether square footage includes walls depends on who is measuring.
If you need the appraisal-style number, upload the plan and trace the exterior. If you need to know how much flooring to order, the room calculator is the right tool.
Frequently asked questions
Is this floor plan square footage calculator free?
Yes. The room-by-room calculator on this page is free with no limit and no account. Uploading a floor plan is free for your first plan too, exports included, so you can measure a plan and download the labeled PDF without paying. After the first plan, further uploads are paid per plan or covered by a monthly plan.
How do I calculate square footage from a floor plan?
If the plan shows room dimensions, multiply each room's length by its width, then add the rooms together. If the plan has no dimensions, or you want the exterior number an appraiser would report, upload the plan, set the scale by clicking both ends of one dimension you know, and trace the outline. The tool converts the drawing into real square footage.
What if my floor plan has no dimensions on it?
You only need one real-world size to set the scale, and it does not have to be a wall. Interior doors are about 36 inches wide, a standard bathtub is 60 inches long, and kitchen counters are 24 inches deep. Click both sides of one of those on the plan, enter its size, and every other measurement follows.
Can I calculate square footage from a PDF floor plan?
Yes. Upload the PDF directly. The tool renders it to an image, lets you pick the page if there is more than one, and you set the scale and trace as usual. Scanned PDFs, CAD exports, and fit-to-page prints all work because the scale comes from a dimension you enter, not from the file.
Should I include the garage in the total?
No. A garage is never living area under ANSI Z765, whether it is attached, detached, finished, or heated. Leave it out of the calculator. If you want to know its size for another reason, add it as its own row and subtract it from the total, or measure it as a separate area in the upload tool.
Does the calculator work for L-shaped or irregular rooms?
The room calculator multiplies length by width, so split an L-shaped room into two rectangles and enter each one. For rooms with angles, bays, or curves, upload the plan instead: the tracing tool follows the actual outline of any shape and calculates the area directly.
How accurate is a room-by-room total?
Good enough for planning, flooring, and comparing listings, but it will usually come in below the appraised number. Room-by-room math uses interior dimensions and skips wall thickness, closets you forgot, and hallways. Appraisers measure the outside of the house, which is why an uploaded plan traced along the exterior gets closer to the appraisal figure.
Can I use this to calculate GLA for an appraisal?
Use the upload tool for that, not the room calculator. Gross living area follows ANSI Z765: exterior measurement of finished, above-grade space, with basements reported on a separate line. Trace the exterior perimeter of each above-grade floor in the tool and it totals GLA the way an appraisal form expects. The room calculator is an estimate only.
Measure Your Floor Plan in Minutes
Upload a plan, set the scale with one known wall, and measure anything: wall lengths, room areas, and total size. Your first measurement is free, no signup required.
Upload Floor PlanRelated reading
- → How to Calculate Square Footage From a Floor Plan
- → How to Read Square Footage on a Floor Plan
- → How to Get Square Footage From a PDF Floor Plan
- → How to Calculate Square Footage of an L-Shaped House
- → Above-Grade vs. Below-Grade Square Footage: What Counts?
- → ANSI Z765 Square Footage Standard: What It Means for Your Home