The Numbers Side by Side

Why Hard Seltzer Is Lower in Calories Than Regular Beer

Regular beer is brewed from malted grain. The fermentation process converts the grain's sugars into alcohol, but it does not convert all of them. The residual, unconverted sugars stay in the final product — and those add calories. A 12 oz Budweiser has about 11 grams of carbohydrates. Almost all of those are residual malt sugars.

Hard seltzers, by contrast, typically start with a sugar-based fermentation that is designed to go nearly to completion. The yeast converts almost all available sugar into alcohol, leaving very little behind. The result is 1–3 grams of carbs per can — and most of the calories come from alcohol itself, not sugar.

Light Beer vs. Hard Seltzer: Nearly Identical

American light beers are made to compete with hard seltzers — and they largely succeed. Miller Lite has 96 calories and 3.2g carbs per 12 oz. Bud Light has 110 calories and 6.6g carbs. Both sit right in the same range as White Claw (100 calories, 2g carbs) or Truly (100 calories, 1g carbs).

If you are choosing between a light lager and a mainstream hard seltzer purely on calories, there is almost no meaningful difference. The choice usually comes down to taste preference and ABV — light beers tend to be 4.2% while many hard seltzers are 5%.

Where Hard Seltzer Clearly Wins

The real gap opens up when you compare hard seltzer to anything in the mid-range beer category or above:

• A regular domestic lager has 40–55 more calories per can than a hard seltzer at the same ABV. Over a 4-drink night that is an extra 160–220 calories.
• A 7% IPA has roughly twice the calories of a hard seltzer, and much of the extra comes from both higher ABV and higher residual carbs.
• A double IPA can hit 280+ calories — nearly three times that of a hard seltzer.

For anyone tracking calories, the shift from regular beer to hard seltzer is a meaningful swap. The shift from light beer to hard seltzer is essentially neutral.

The ABV Factor

One thing that makes the comparison slightly tricky is that not all hard seltzers are the same ABV. The mainstream brands (White Claw, Truly, Bud Light Seltzer) are 5%. But "hard seltzer" style drinks now range from 3.5% to 12% ABV. A hard seltzer at 8% will have significantly more calories than one at 5%, because alcohol itself is the primary calorie source.

Similarly, a 4.2% light lager has fewer alcohol calories than a 5% hard seltzer, even though the seltzer has fewer carbs. When ABV differs, you need to look at the total calorie count — not just the carbs — to make a fair comparison.

What About Carbs Specifically?

On a low-carb or keto diet, carbohydrates matter more than total calories. Here the distinction is sharper:

• Hard seltzer: 1–3g carbs per can. Essentially zero on most tracking apps.
• Light beer: 3–7g carbs. Low, but not negligible for strict keto.
• Regular beer: 10–15g carbs. One can is a significant portion of a strict daily carb budget.

If carb restriction is the goal, hard seltzer is the clear winner across the board. A straight spirit (vodka, tequila, whiskey) with soda water is also zero carbs and tends to be the most flexible option at a bar.

Bottom Line

• Hard seltzer beats regular beer by ~40–50 calories per can at the same ABV.
• Hard seltzer and light beer are virtually tied on calories; seltzer wins on carbs.
• Craft and high-ABV beers can be 2–3x the calories of hard seltzer.
• Alcohol content (ABV) is the biggest single driver — higher ABV means more calories, regardless of whether it is beer or seltzer.