How this carb calculator works
First, we estimate your maintenance calories. We use the Mifflin-St Jeor equation for your resting burn, then multiply it by your activity level.
Next, we adjust for your goal:
- Lose fat: 20% fewer calories than maintenance
- Maintain or healthy aging: your maintenance calories
- Build muscle: 10% more calories
- On a GLP-1 medication: 15% fewer calories
We never go below 1,200 calories a day for women or 1,500 for men.
Then we turn your calories into grams of carbs. The Institute of Medicine says adults should get 45% to 65% of their calories from carbs. Each gram of carbs has 4 calories. So on 2,000 calories, 45% is 900 calories, or 225 g. And 65% is 1,300 calories, or 325 g.
What your result means
Your result shows three numbers:
- Healthy range: 45% to 65% of your calories, in grams.
- Minimum for adults (RDA): 130 g a day. It is based on the glucose your brain needs to work well.
- Our protein-first split: the carbs left after we set your protein and give 30% of calories to fat. Because protein comes first, this number can land near or even below the low end of the range, especially when you pick lose fat or build muscle.
Any number in the range is a reasonable goal. If you are active, the higher end may feel better. If you want to lose weight and like more protein and fat, the lower end may suit you.
Tips for choosing carbs
- Choose whole grains, beans, fruit, and vegetables most of the time.
- Limit added sugar, like soda, sweets, and sweetened drinks.
- Pair carbs with protein at meals to stay full longer.
- Watch portions of rice, pasta, and bread, since they add up fast.
Want fewer carbs?
If you want to go much lower, see our keto calculator. For a full plan with protein, carbs, and fat, use the macro calculator. Our guide on how many carbs per day explains the options in more detail.
If you have diabetes or take medicine for blood sugar, talk to your doctor or a registered dietitian before changing your carb intake.