Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Climate
Evapotranspiration Calculator
Estimate monthly potential evapotranspiration (PET) from average temperature, daylight hours, and days in the month using a simplified Thornthwaite-style formula. Returns millimetres of water lost per month.
Fill in the required fields to see your result.
Climate
Climate Normal Calculator
Compute a climate anomaly as the standardised z-score of a current value against the 30-year average and standard deviation. Values outside ±2 indicate statistically unusual conditions.
Fill in the required fields to see your result.
Key differences
| Evapotranspiration Calculator | Climate Normal Calculator | |
|---|---|---|
| Category | Climate | Climate |
| Inputs required | 3 | 3 |
| Result | Potential Evapotranspiration (mm/month) | Climate Anomaly (standard deviations) |
| What it does | Estimate monthly potential evapotranspiration (PET) from average temperature, daylight hours, and days in the month using a simplified Thornthwaite-style formula. Returns millimetres of water lost per month. | Compute a climate anomaly as the standardised z-score of a current value against the 30-year average and standard deviation. Values outside ±2 indicate statistically unusual conditions. |