Beer SRM Color Calculator
The Standard Reference Method (SRM) is used to describe beer color on a numeric scale, where 2 is pale straw (like a light lager) and 40+ is nearly opaque black (like a stout). Homebrewers use SRM to design recipes that match target style guidelines. This calculator uses the Morey formula, which is more accurate across a wide color range than the older Mosher formula. Enter each grain in your recipe with its weight and Lovibond color rating. The calculator adds up the Malt Color Units (MCU) and applies the Morey formula to estimate your beer's final color in both SRM and EBC units.
Morey SRM formula
MCU = (grain_lbs * lovibond) / batch_gallons (sum for all grains)
SRM = 1.4922 * MCU^0.6859
EBC = SRM * 1.97
This formula is accurate for beers up to SRM 40. For very dark beers (stouts, porters), the Morey formula may slightly underestimate darkness compared to actual spectrophotometric measurement.
SRM color reference
- SRM 1-3: Pale straw (light lager, wheat beer)
- SRM 4-8: Gold (pilsner, blonde ale, saison)
- SRM 9-14: Amber / orange (amber ale, Vienna lager)
- SRM 15-22: Deep amber / copper (ESB, brown ale)
- SRM 23-30: Brown (porter, brown ale)
- SRM 31-40+: Near black to black (stout, schwarzbier)
Beer SRM: frequently asked questions
What is SRM in beer?
SRM (Standard Reference Method) is the standard scale for measuring beer color in North America. Values range from 1-2 (pale straw, like light lager) to 40+ (black, like stout). EBC (European Brewing Convention) is the European equivalent: EBC = SRM * 1.97.
How is SRM calculated?
SRM is calculated using the Morey formula: SRM = 1.4922 * MCU^0.6859, where MCU (Malt Color Units) = (grain_weight_lbs * grain_color_Lovibond) / batch_gallons. Add MCUs from all grains, then apply the Morey formula.
What is Lovibond color in malt?
Lovibond (L) is the color unit used for malts. Pale malt is 1-3 L, crystal malts range from 10-120 L, chocolate malt is around 350 L, and black patent malt is 500+ L. Maltsers print the Lovibond value on the bag.
How does batch size affect beer color?
Larger batches (more gallons) with the same grain bill produce lighter colored beer because the color compounds are more diluted. Smaller batches with the same grain bill are darker.
What is the difference between SRM and EBC?
SRM and EBC measure the same property (light absorption at 430nm wavelength) but use different scales. EBC = SRM * 1.97. American homebrewing recipes use SRM; European recipes use EBC. Most grain supplier data sheets list Lovibond, which is approximately the same as SRM for malts.
Official sources
- American Society of Brewing Chemists: ASBC Methods of Analysis.
- Brewers Association: Beer Style Guidelines.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.