Rainwater Harvest
Calculate Rainwater Harvest instantly with the exact formula and a worked example.
Rainwater Harvest
Roof area (in plan)m²
Rainfall per monthmm
Roof runoff coefficient
Litres/month
5,100L
In cubic metres
5.1m³
200 L barrels
25.5
More about: Rainwater Harvest
What it calculates
The “Rainwater Harvest” calculator computes Litres/month in L from 3 parameters: roof area (in plan) (m²), rainfall per month (mm), roof runoff coefficient.
Estimates environmental impact and carbon footprint.
Example calculation
With parameters Roof area (in plan) = 100 m², Rainfall per month = 60 mm, Roof runoff coefficient = 0.85 the result is 5,100 L (Metal, tiles ≈ 0.85–0.9; bitumen roofing ≈ 0.8; green roof ≈ 0.3–0.5).
How to use
- Enter roof area (in plan), rainfall per month and roof runoff coefficient — each field above is adjustable with a slider.
- Litres/month (L) is calculated automatically as you type.
- Check the worked example below to see the formula applied to real numbers.
- Copy the result or bookmark this calculator.
Related calculators
FAQ
How is Rainwater Harvest calculated?
The Rainwater Harvest calculator computes Litres/month (in L) from roof area (in plan), rainfall per month, roof runoff coefficient. Enter your values above and the exact formula is applied instantly; a worked example with real numbers is shown below.
Is the Rainwater Harvest calculator free?
Yes. It is completely free, needs no signup, runs entirely in your browser, and sends no data to any server.
More calculators in this category
Explore related free tools