Rainfall Deficit Surplus Calculator
Compare actual rainfall with normal and see whether you have a surplus or deficit.
Compare Your Options And Get Clear Answers
Compare actual rainfall with normal and see whether you have a surplus or deficit.
Rainfall Deficit Surplus Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
Enter Values
Fill in each field with your own numbers.
Calculate
Results update as you change the inputs.
Review
Read the breakdown and the explanation.
Adjust
Change values to compare scenarios.
Rainfall Quick Guide
Typical values for reference.
| Result | Meaning | Garden | Note |
|---|---|---|---|
| +20 mm | Wet | Skip watering | Surplus |
| 0 | Normal | Usual | Average |
| -20 mm | Dry | Water | Deficit |
| -40 mm | Very dry | Water deeply | Drought risk |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Rainfall Deficit Surplus Calculator FAQ
Answers to common questions about this calculator.
Rain above the normal amount for the period.
It gives a quick estimate of rainfall deficit surplus from the values you enter.
No. It is a planning estimate, so check important figures with a professional or official source.
Yes. Edit any field and the result updates when you calculate.