Cost per Square Foot Calculator

Turn a repair quote into a cost per square foot — and turn any $/sq ft planning band back into a total — so you can compare bids on the same footing.

Planning estimate: this is a planning estimate from the numbers you enter and standard reference quantities — not a bid or a contract. Get itemized written quotes from licensed contractors and confirm measurements before you commit.

Calculator

$
The quoted or planned cost.
sq ft
Square footage the price covers.
Cost per square foot$10.20 /sq ft
Project total$10,200.00
Area1,000 sq ft
Reverse check1,000 × $10.20 = $10,200.00

$10,200.00 over 1,000 sq ft is $10.20/sq ft. Use it to compare a quote to typical per-sq-ft planning bands — and to turn any band back into a total (area × $/sq ft).

Two quotes are hard to compare when they cover different areas. Normalizing a price to cost per square foot puts them side by side: a $10,200 job over 1,000 sq ft and a $16,000 job over 1,600 sq ft are the same $10.20/sq ft, even though the totals look very different.

This calculator works both ways. Enter a total and an area to get $/sq ft, and use the reverse (area × $/sq ft) to turn a per-square-foot planning band back into a total for a space you are sizing up.

The value of the metric is that it strips size out of the comparison. Contractors quote whole jobs, and a bigger basement will always cost more in absolute dollars — that tells you nothing about whether the price is fair. Reduce each bid to dollars per square foot and the size difference disappears, leaving the thing you actually want to compare: the rate each contractor is charging for the same kind of work.

Formula

The core is a single division, with the reverse for planning:

$/sq ft = total ÷ area
total = area × $/sq ft

The two are inverses, so the tool also shows a reverse check that multiplies straight back to your total.

Worked example

A $10,200 basement waterproofing job over 1,000 sq ft:

  • Cost per square foot: $10,200 ÷ 1,000 = $10.20/sq ft
  • Reverse check: 1,000 × $10.20 = $10,200

Now the same $10.20/sq ft applied to a 1,600 sq ft basement would plan out at about $16,320 — a quick way to scale a known price to a different footprint.

What $/sq ft can and can't tell you

Cost per square foot is a comparison and planning aid, not a price you can hold a contractor to. Fixed costs (mobilization, a sump, permit fees) don’t scale with area, so a small job usually shows a higher $/sq ft than a large one, and a specialized repair (piering, exterior excavation) can be far higher than a broad surface treatment.

Use it to sanity-check a bid against typical cost-per-square-foot planning bands — remembering those bands are a labeled planning aid, not current market pricing. This is a planning estimate on figures you enter; get itemized written quotes before you decide.

Match the area to the work, or the number is meaningless. A wall coating is priced over wall area, not floor area; drain tile is priced over the footing perimeter in linear feet, not square feet at all; a slab is priced over its footprint. Feeding the wrong area into the division produces a tidy-looking $/sq ft that compares nothing to nothing. When two quotes measure the job differently, reconcile the areas first, then convert.

Frequently asked questions

Why does a small job cost more per square foot?
Because some costs are fixed no matter the size — getting the crew and equipment on site, a sump, permit fees. Spread those over a small area and the per-square-foot number rises; spread them over a large area and it falls. That is normal, not a red flag.
Can I compare two quotes just by $/sq ft?
It is a good first pass, but make sure the two quotes cover the same scope and the same area. A cheaper $/sq ft that skips drainage or a sump isn’t really cheaper — it is a different job.
How do I go from a $/sq ft band back to a total?
Multiply: total = area × $/sq ft. Enter the area you are pricing and read the reverse check, or use a planning band from our reference tables to ballpark a total for a space.
Is the $/sq ft here a market price?
No. This tool only divides the numbers you type in. It stores no prices, so nothing goes stale; any market context comes from your own quotes and our clearly-labeled planning bands, not a live price feed.
What area should I use?
Use the area the price actually covers — the basement floor for a slab treatment, the wall area for a coating, the footing perimeter for drain tile. Matching the area to the work is what makes the $/sq ft meaningful.
Is a lower cost per square foot always better?
Not by itself. A lower rate that leaves out drainage, a sump or proper prep is cheaper only because it is doing less. Confirm the two quotes cover the same scope before you let the $/sq ft decide — price per unit only means something when the unit is the same job.

Related calculators

Repair Budget Allocator by %Split a foundation or basement repair budget across foundation, waterproofing, drainage and labor by percentage. Free calculator with editable planning splits.Basement Waterproofing CostEstimate basement waterproofing cost from your perimeter and the price per linear foot you enter, for interior drain tile, exterior membrane or sealant methods.Concrete Slab CostCalculate concrete slab cost: cubic yards from area and thickness, times your $/cu yd, plus your labor per square foot. A planning estimate on your own numbers.