Two numbers appear on almost every craft beer label, can, and tap handle: ABV and IBU. They tell you how strong and how bitter a beer will be before you take a sip — if you know how to read them. Understanding these two metrics will immediately improve how you choose, order, and enjoy beer.
ABV: Alcohol By Volume
ABV stands for Alcohol By Volume — the percentage of the total liquid that is ethanol (alcohol). It’s the global standard measurement for how strong an alcoholic drink is.
A beer with 5% ABV contains 5 milliliters of pure alcohol for every 100 milliliters of beer. Simple.
How ABV Gets Calculated
ABV is determined by measuring two gravity readings: the original gravity (OG) — the density of the wort before fermentation — and the final gravity (FG) — the density after yeast has consumed the sugars. The difference tells you how much sugar was converted to alcohol.
The simplified formula:
ABV ≈ (OG − FG) × 131.25
This is exactly what homebrewers use a hydrometer to calculate. If you’re brewing at home, our guide to understanding original and final gravity explains every step. The American Homebrewers Association also publishes a good primer on gravity measurements for beginners.
The measurement is standardized internationally and regulated by alcohol authorities in most countries. The Brewers Association provides labeling guidance for US craft breweries.
ABV Ranges Across Beer Styles
| Category | ABV Range | Examples |
|---|---|---|
| Session / Low-ABV | 2.5–4.5% | Berliner Weisse, session IPA, mild ale |
| Standard Strength | 4.5–6.0% | Lager, pale ale, hefeweizen |
| Strong | 6.0–8.5% | IPA, Belgian tripel, saison |
| Very Strong | 8.5–12% | Imperial stout, doppelbock, barleywine |
| Extreme | 12%+ | Extreme barrel-aged barleywines, freeze-concentrated beers |
The average beer you’ll encounter at a craft brewery sits between 5–7% ABV. For context, standard wine is 12–14% ABV; standard spirits are 40–50%.
ABV and “Feeling” the Beer
ABV doesn’t tell the whole story of how a beer affects you — carbonation level, drinking pace, body weight, and food consumption all play a role. But as a quick rule: every additional percentage point above 5% is meaningful. A 9% Imperial Stout is nearly double the alcohol of a 5% lager.
IBU: International Bitterness Units
IBU stands for International Bitterness Units — a measurement of the concentration of iso-alpha acids in beer, which are the primary bittering compounds derived from hops.
IBU is a chemical measurement (in parts per million) standardized by the Master Brewers Association of the Americas and adopted internationally. Higher IBU = more bitter compounds present in the beer.
The IBU Scale in Practice
Here’s where things get interesting: IBU is not a perfect predictor of how bitter a beer tastes. Perceived bitterness is influenced by:
- Residual sweetness — A malt-forward beer with 50 IBU can taste less bitter than a dry beer with 30 IBU
- Carbonation — Higher carbonation can sharpen perceived bitterness
- Hop variety and timing — Late-addition and dry hops contribute aroma compounds that can change bitterness perception
- ABV — Higher alcohol can mask bitterness
That said, IBU remains the most useful number for comparing styles:
| IBU Range | Examples | Perceived Bitterness |
|---|---|---|
| 0–10 | Witbier, Berliner Weisse | Very low; almost none |
| 10–20 | Hefeweizen, stout | Low to mild |
| 20–40 | Pale ale, amber ale, pilsner | Moderate; hop presence noticeable |
| 40–60 | IPA, ESB | Moderately high; clearly bitter |
| 60–80 | West Coast IPA | High; dry and assertive |
| 80+ | Double IPA | Very high; dominant bitterness |
The NEIPA Exception
New England IPAs (hazy IPAs) have helped expose the limits of IBU as a consumer guide. A hazy IPA may show 40–60 IBU on paper, but due to the biotransformation of hop compounds during dry hopping, the beer often tastes much softer and less bitter than that number suggests. CraftBeer.com has discussed this phenomenon extensively.
Conversely, a very dry, high-carbonate pilsner with 30–35 IBU can taste quite sharp. Context matters.
SRM: The Third Number (Sometimes)
You’ll occasionally see a third number on craft beer labels: SRM (Standard Reference Method), which measures beer color on a scale from 1 (pale straw) to 40+ (opaque black). While less common on consumer labels, it’s useful:
- 1–3 SRM: Very pale (lite lager)
- 4–8 SRM: Golden (pilsner, pale ale)
- 9–14 SRM: Amber (Märzen, amber ale)
- 15–22 SRM: Dark amber to brown (porter, brown ale)
- 23–40+ SRM: Dark brown to black (stout)
What the Label Doesn’t Tell You
ABV and IBU give you useful benchmarks, but they don’t tell you about:
- Flavor notes — What actual aromas and tastes to expect
- Mouthfeel — Body, carbonation, creaminess
- Freshness — How long the beer has been packaged (critical for IPAs)
- Yeast character — Whether it’s funky, fruity, or neutral
This is why apps like Untappd and sites like BeerAdvocate are useful — they add crowd-sourced flavor descriptions to the raw numbers.
Practical Tips for Using These Numbers
- Under 5% ABV and under 30 IBU? Very approachable — good for newcomers or drinking over a long session
- Over 8% ABV? Treat it like wine — sip, don’t gulp, and eat beforehand
- IBU over 60? Expect assertive bitterness unless the style is a hazy IPA
- High ABV + high IBU? Double IPA territory — complex and intense
- Low ABV + high IBU? Session IPA — refreshing bitterness without the buzz
The BJCP Style Guidelines list both OG and IBU ranges for every recognized beer style, making it a useful reference when you want to understand what “correct” looks like for a given category.
Reading the Label: Quick Checklist
When you pick up a new beer, scan for:
- ABV — Know what you’re getting into
- IBU (if listed) — Calibrate bitterness expectations
- Style name — The most useful shorthand
- Packaging date — Fresher is almost always better, especially for hoppy beers
- Brewery location — Local and fresh beats traveled and stale for many styles
Wikipedia’s summary of alcohol by volume gives a helpful international context for how ABV is standardized and measured across different types of beverages.
Putting It All Together
Understanding ABV and IBU becomes most useful when you pair it with style knowledge. Once you know that a West Coast IPA will land around 6.5% ABV and 65 IBU, and a hefeweizen will be 5% ABV and 12 IBU, you can set your expectations accurately before you open the can. For a comprehensive map of the style landscape and where these numbers sit for each family, read the beer style guide for beginners — it puts every major style in context.
The Brew Professor Takeaway
ABV tells you how strong the beer is; IBU gives you a rough guide to bitterness. Neither number tells the whole story, but together they’re the two most useful pieces of data on any beer label. Once you internalize the ranges — and understand that IBU interacts with malt sweetness and carbonation — you’ll have a much clearer picture of what any beer will taste like before the glass reaches your lips.
