Understanding SRM: How to Estimate Beer Color

Beer color is one of the first things you notice before you even take a sip. The Standard Reference Method (SRM) is the standard scale used to describe beer color in North America. Here’s how it works and how to predict it from your recipe.

The SRM Scale

SRM ranges from pale lagers at 2-3 SRM to imperial stouts pushing 40+ SRM:

Calculating Malt Color Units (MCU)

The first step is calculating MCU for each grain:

MCU = (Weight in lbs × Lovibond) / Volume in gallons

For example, 7 lbs of 3°L Maris Otter in 5 gallons:

MCU = (7 × 3) / 5 = 4.2

Morey’s Formula (Recommended)

The most widely used formula for converting MCU to SRM:

SRM = 1.4922 × MCU^0.6859

This works because the relationship between MCU and perceived color isn’t linear — light grains contribute more color than the math suggests, and dark grains contribute less.

Alternative Formulas

• Mosher: SRM = 0.3 × MCU + 4.7 (better for very dark beers)
• Daniels: SRM = 0.2 × MCU + 8.4 (alternate for dark beers)

Our SRM Calculator shows all three formulas side-by-side, plus a visual SRM color scale with your beer’s position highlighted.

Key Takeaways

• Use Morey’s formula for most homebrew (under 30 SRM)
• Record Lovibond values carefully — a 10°L difference matters
• Crystal/caramel malts contribute significant color even in small amounts
• Our free SRM calculator shows all three formulas and includes a visual color bar

Try the free SRM Color Calculator — no sign-up needed. Want to track color readings over time on your batches? Start a free trial.