Drain fall & gradient calculator

Calculate the gradient of a measured drain run.

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Your measurements

Enter your project values. Your estimate updates as you type.

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m
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Example values are a starting point. Check product yields and specifications before ordering.

YOUR ESTIMATE

Gradient

1%
Slope angle0.573 °
Sloping length10 m

Calculated from your measurements.

How it's calculated

Gradient (%) = rise ÷ horizontal run × 100. Angle = arctan(rise ÷ run).

Calculations use consistent units for your selected measurements. Whole purchase quantities are rounded up.

What this estimate includes

This reports a measured gradient. Required gradients and drainage sizing depend on the applicable design and local rules.

Quantity and arithmetic estimates only. Use project specifications for installation and design requirements.

Keep your project moving.