Pool Evaporation Calculator
Estimate how much water your pool loses to evaporation each day based on pool area, temperature, humidity, and wind.
Estimated Daily Water Loss
Pool evaporation depends on surface area, temperature, humidity, and wind speed. A simplified formula:
Evaporation Rate ≈ Area × Evaporation Factor × (1 − Humidity/100) × Wind Multiplier
Typical pool evaporation rates:
- Cool, humid climate: 0.05–0.1 inches/day
- Moderate climate: 0.1–0.25 inches/day
- Hot, dry climate: 0.25–0.5 inches/day
Factors that increase evaporation:
- Higher air and water temperature
- Lower humidity
- Higher wind speed
- Larger pool surface area
- Higher water temperature relative to air temperature
Water loss context:
- A typical 12×24 ft pool losing 0.25 in/day = ~45 gallons/day
- Monthly loss in a hot climate: 1,000–2,500 gallons
Tips to reduce pool evaporation:
- Use a pool cover (reduces evaporation by 90–95%)
- Plant windbreaks around the pool
- Lower water temperature slightly
- Use liquid solar covers (reduce by 15–30%)