Free tool

How full is my tank?

Measure your water depth with a stick or your gauge, and this calculator turns it into litres — and into days, at three usage levels.

Tank size (typical heights — check your tank's label)

Capacity (litres) Tank height, inside (cm)

Measured water depth (cm)

People in the house

Assumes a uniform (straight-walled) tank. For tapered tanks, treat results as an estimate.

500 Lin the tank right now

Usage level	Lasts about
Normal household (±150 L/person/day)	—
Rationed outage mode (±50 L/person/day)	—
Drinking & cooking only (±5 L/person/day)	—