SRM Beer Color Calculator (Morey)

This calculator predicts the color of your beer in SRM (Standard Reference Method) and EBC using Daniel Morey’s formula, the de-facto standard in modern brewing software. Enter each malt’s weight and Lovibond color along with the batch volume, and the tool returns a numeric SRM/EBC value plus an approximate on-screen color swatch.

How it works

Beer color starts from Malt Color Units (MCU), the volume-weighted sum of each grain’s color contribution:

MCU = Σ(weight_lb × color_°L) / volume_gal

Because light absorption is non-linear, raw MCU overstates dark colors. Morey fit a power curve to real brewing data:

SRM = 1.4922 × MCU^0.6859

EBC, the European scale, is then:

EBC = SRM × 1.97

Worked example

A simple amber ale in 5 gallons:

Apply Morey:

SRM = 1.4922 × 15.2^0.6859 ≈ 1.4922 × 6.55 ≈ 9.8 SRM
EBC = 9.8 × 1.97 ≈ 19.3 EBC

That places the beer in the amber range, which matches the recipe intent.

Understanding SRM and EBC as color scales

SRM (Standard Reference Method) is the American color scale used most widely in homebrew software and American commercial brewing. It runs numerically from 1 (water-pale lager) upward with no practical maximum, though beers above about 40 SRM become visually indistinguishable from black.

EBC (European Brewing Convention) is the European equivalent. The conversion EBC = SRM × 1.97 means EBC values are nearly double the SRM value, so an American pale ale at 5 SRM is about 10 EBC. When reading European malt spec sheets, you will often see °EBC; divide by 1.97 (or multiply by 0.508) to convert to the °L equivalent used in this formula.

Lovibond (°L) is the measurement printed on malt spec sheets and used as the input to the MCU formula. Base malts like two-row and Maris Otter sit around 1.8–3 °L. Specialty malts range from crystal/caramel varieties at 10–120 °L through to heavily roasted malts like black patent and chocolate at 300–550 °L.

How grain choice affects color

A small amount of a very dark grain contributes colour out of proportion to its weight, while large quantities of a pale base malt contribute relatively little. For example, adding 0.25 lb of Roasted Barley (300 °L) to a 5-gallon batch contributes 15 MCU, the same as 1 lb of Crystal 75. This asymmetry means colour is primarily controlled by specialty grain color, not quantity.

Common color targets by style:

Why Morey is the standard formula

Three MCU-based formulas exist: Mosher’s, Daniels’, and Morey’s. Mosher (SRM = 0.3 × MCU + 4.7) and Daniels (SRM = 1.73 × MCU^0.64) both diverge significantly from observed SRM at either low or high MCU values. Morey’s formula (SRM = 1.4922 × MCU^0.6859) fits real brewing data best across the widest range. Most homebrewing software (BeerSmith, Brewfather, and others) defaults to Morey for this reason.

Tips and notes

• Use post-boil volume. Boiling concentrates color, but it is the final packaged volume that determines how diluted the color appears. Some brewers use pre-boil volume and add an extraction efficiency adjustment, but post-boil is simpler and more common.
• The on-screen swatch is an approximation derived from SRM. Real perceived color depends on beer clarity, glass shape, and lighting — a cloudy wheat beer looks much paler than a crystal-clear lager at the same SRM.
• For very dark beers (stouts, 40+ SRM) any formula is only a rough guide — visually they all read as “black.” Morey stays sensible far better than a raw MCU sum, which would balloon to absurd numbers.
• Malt spec sheets sometimes give color in °EBC rather than °L. Convert with °L = °EBC ÷ 1.97 before entering the value.
• Cross-check against the Daniels MCU formula for a second opinion on the same grain bill, especially for very pale or very dark recipes.