Renovation Cost per Square Foot Calculator
The universal normalizer: divide any renovation total by its floor area to get a clean $/sq ft you can compare across quotes — and multiply back to check a total.
Calculator
$135,000.00 over 1,800 sq ft is $75.00/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).
Formula
Cost per square foot is just the total spread over the area — and it reverses cleanly:
$/sq ft = project total ($) ÷ floor area (sq ft)
total = area (sq ft) × $/sq ft (the reverse check)
This is the single most useful number for comparing renovations of different sizes. A $135,000 quote and a $95,000 quote are hard to compare until you normalize them by area; once both are in $/sq ft, you can line them up against each other and against typical planning bands.
Worked example
Take a $135,000 renovation of an 1,800 sq ft house:
$135,000 ÷ 1,800 = $75.00/sq ft
Reverse it to confirm: 1,800 × $75.00 = $135,000. Now that you have $75/sq ft, you can apply it to a different-sized version of the same project — a 2,400 sq ft house at the same band would be 2,400 × $75 = $180,000 — using the whole-house renovation cost tool.
Using $/sq ft honestly
Cost per square foot is a comparison and planning aid, not a quote. It flattens away everything that actually varies between projects — finish level, structural work, how many kitchens and baths, site access, local labor — into one blended number. That makes it perfect for a first-pass sanity check and useless as a promise. Treat a $/sq ft band the way you would treat miles per gallon: a helpful yardstick, not a guarantee for any specific trip.
The most reliable band is one you derive yourself. Take a real quote you trust, divide by the area here, and reuse that $/sq ft to scope a larger or smaller version of the same work. Pair it with the gut renovation tool for down-to-studs scope, the budget allocator to split the total across rooms and trades, and the room addition tool, which uses the same $/sq ft logic for new square footage.
Because the underlying work usually includes structural, electrical and plumbing scope, keep the estimate framed as a budget: verify with itemized written quotes and use licensed pros and permits.