calcs.homes
calcs.homes
Enter your pool's surface size and pick the conditions closest to yours to estimate how much water evaporation is costing you.
Estimate only — actual evaporation varies with humidity, sun exposure, and water temperature.
We multiply pool surface area (length times width) by a daily depth-loss rate you select — 1/8 in for a calm or covered pool, 1/4 in for average conditions, up to 1/2 in for hot, windy, or heated water — then convert that volume to gallons. Weekly loss simply multiplies the daily figure by 7.
These depth-loss rates reflect typical pool-industry ranges for how fast an open water surface loses moisture to the air, driven mainly by wind and sun exposure rather than water temperature alone. Comparing your estimated loss against the pool's actual water-level drop helps separate normal evaporation from a leak — a cover is the single biggest lever for cutting the real number, since it blocks both wind and direct sun.
Typically 1/4 inch of depth per day under average conditions, more in hot, dry, or windy weather, or with a heated pool. A pool cover can cut this significantly.
Try a bucket test: place a bucket on a pool step filled to the same level as the pool, mark both water lines, and check after 24 hours. If the pool has dropped noticeably more than the bucket, you likely have a leak, not just evaporation.