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Wort dilution calculator: water to reach target gravity

For unfermented wort, final volume ≈ current volume × current gravity points ÷ target gravity points. Diluting 20 L at 1.060 to 1.050 requires about 4 L of water, giving 24 L total.

BrewMyBeer editorial · Sources checked 24 September 2026 · Calculated examples, not laboratory measurements. How we create content

Interactive tool

Calculate your batch

Change the example values. Inputs stay in your browser.

Measure before adding top-up water.

Use a well-mixed sample.

Must be no higher than the current gravity.

Confirm the reading before changing the batch

Mix the wort and confirm volume and temperature-corrected gravity. A concentrated sample from poorly mixed top-up wort can suggest a problem that the full batch does not have.

Use the same temperature basis for the measurements. This is the usual gravity-points approximation, not an exact solution based on extract mass and density tables. The displayed decimal places do not imply that level of real-world accuracy.

Water changes more than original gravity

Top-up water reduces concentrations of extract, colour and bitterness. In the example, 20 L becomes 24 L, so ingredients already dissolved in the original wort are distributed across 20% more volume. Review the intended flavour as well as the target SG.

Use water suitable for brewing and an appropriate sanitary process for the stage of production. Cold-side additions need particular care with contamination and oxygen exposure. This tool does not prescribe a treatment method or certify the batch for packaging.

Before you use the result

  • Adding water cannot raise gravity.
  • A target equal to current gravity requires no water.
  • Do not use this wort model to blend finished spirits to a labelled strength.

A quick learning check

Why does reducing 60 gravity points to 50 require 24 L total rather than 22 L?

Try a craft decision game →

Sources & further reading

These references explain the methods and limitations. The worked examples and learning questions on this page are BrewMyBeer calculations, not claims of hands-on testing.