Skip to content
Wavo Calculator
Sign in Open calculators

Spa Volume Calculator

Spa gallons from shell dimensions plus fill cost. Small volumes need teaspoon precision, not gallon guesses.

Inputs

Inputs and assumptions

Inside length of the spa shell in feet.

Inside width of the spa shell in feet.

Water depth, not shell height. Most spas hold 250-500 gallons.

From your water bill, per 1,000 gallons.

Result

Cost to fill (USD)
$6.60
Spa volume (gal)
1,100
Measure water edge to water edge. Estimates assume standard shapes; verify odd pools against dose response.

Related calculators

Calculator

Backwash Water Loss Calculator

Gallons per backwash cycle and per month from filter GPM, minutes, and frequency, plus water cost.

Outputs: Gallons per backwash (gal) · Gallons per month (gal) · Monthly water cost (USD)

Open calculator

Calculator

Oval Pool Volume Calculator

Oval above-ground gallons from longest axis, shortest axis, and depth, plus fill cost at your water rate.

Outputs: Oval pool volume (gal) · Cost to fill (USD)

Open calculator

Calculator

Pool Cover Savings Calculator

Gallons and dollars a cover saves versus uncovered evaporation at your water rate.

Outputs: Water lost uncovered (gal) · Gallons saved with cover (90%) (gal) · Money saved (USD)

Open calculator

Guides

01 How to Measure Pool Volume: Dimensions, Depth, and Gallons 02 Evaporation and Pool Covers: Calculate Water Loss and Savings

Related articles

01 Evaporation and Pool Covers: Calculate Water Loss and Savings 02 How to Measure Pool Volume: Dimensions, Depth, and Gallons

Workspace

Keep the assumptions with the result.

Save this calculation to return to the inputs, result, and report from your private workspace.

Sign in to save Create account

Sign in or create an account to save this calculation.