Estimate a daily carbohydrate range in grams from your calorie needs and compare it with the published 45 to 65% guideline. Metric and US units.
This is a general estimate for educational use. It is not medical advice, a diagnosis or a treatment plan. Talk to a doctor, registered dietitian or other qualified professional before you change your diet, exercise or health care.
| Share | Grams a day | From carbs | Per meal | g per kg |
|---|
| Goal | Calories | 45%, g | Your pick, g | 65%, g |
|---|
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A carbohydrate calculator estimates how many grams of carbohydrate fit a daily calorie target. It finds your daily calories from age, sex, height, weight and activity, then multiplies by a share of energy and divides by 4 kcal per gram. The published range for adults is 45 to 65 percent of calories.
This carbohydrate calculator shows that range in grams, then lets you pick your own share inside it and see the grams, the calories and the amount per meal. It sets the result beside the 130 g Recommended Dietary Allowance, a fibre reference and the added sugar limit. The calorie part uses the same formulas as our calorie calculator and TDEE calculator, so the same person gets the same calories on each page. For other everyday sums, see the free online calculators.
| Person and goal | Calories | 45% | 55% | 65% |
|---|---|---|---|---|
| Woman, 30 y, 165 cm, 65 kg, maintain | 2,124 | 239 g | 292 g | 345 g |
| Man, 30 y, 180 cm, 80 kg, maintain | 2,759 | 310 g | 379 g | 448 g |
| Same woman, lose 0.5 kg a week | 1,574 | 177 g | 216 g | 256 g |
| Same woman, lose 1 kg a week | 1,200 (held at the 1,200 kcal minimum) | 135 g | 165 g | 195 g |
The first answer is already on screen. Change any number and it updates at once, with no Calculate button.
Pick female or male for the formula, then type age, height and weight in metric or US units. Age must be 18 to 100, because these formulas are for adults.
Select one of five activity levels and, if you like, a weekly weight goal. The goal changes the calorie target, and a safety floor stops the target from falling below the lowest figure in the US guidelines.
The big number is the published range in grams. Tap 45 to 65 percent, or type your own share, to see one figure inside it with calories, grams per kilogram and the split across 2 to 6 meals.
See the fibre reference and the added sugar limit for your calories, open the tables by share of energy and by weight goal, and read the working. Copy the result or share a link.
Three steps turn a body into a gram figure. First, an equation estimates resting energy (BMR). Second, an activity multiplier turns BMR into maintenance calories (TDEE), and a goal adds or removes calories. Third, the carbohydrate share of those calories is divided by 4, the energy in a gram of carbohydrate.
The default formula is Mifflin St Jeor, derived from 498 healthy adults aged 19 to 78 and published in 1990. Revised Harris-Benedict and Katch-McArdle are one tap away under the results. Calories and grams are rounded to whole numbers for display only, and the working shows every step. For percentage sums in general, see the percentage calculator.
| Value | Formula |
|---|---|
| Mifflin St Jeor | Men 10w + 6.25h − 5a + 5; women 10w + 6.25h − 5a − 161 |
| Revised Harris-Benedict | Men 88.362 + 13.397w + 4.799h − 5.677a; women 447.593 + 9.247w + 3.098h − 4.330a |
| Katch-McArdle | 370 + 21.6 × lean body mass, where lean body mass = w × (1 − body fat % ÷ 100) |
| Maintenance (TDEE) | BMR × 1.2, 1.375, 1.55, 1.725 or 1.9 |
| Goal | kg per week × 7,700 ÷ 7 (US units: lb × 3,500 ÷ 7); deficit capped at 1,000 kcal a day |
| Carbohydrate grams | Daily calories × share % ÷ 100 ÷ 4 |
| Fibre and added sugar | Calories ÷ 1,000 × 14; calories × 10% ÷ 4 |
These are the figures the calculator compares against. Each comes from a document listed under Sources.
| Value | Figure | Source |
|---|---|---|
| Carbohydrate range (AMDR) | 45 to 65% of energy | Dietary Guidelines 2015-2020, Appendix 7, from the Dietary Reference Intakes |
| Carbohydrate RDA | 130 g a day for adults | Same appendix |
| Fibre | 14 g per 1,000 kcal, the basis of the Adequate Intake | Same appendix |
| Added sugars, 2020-2025 edition | Less than 10% of calories, about 50 g at 2,000 kcal | Dietary Guidelines added sugars fact sheet |
| Added sugars, 2025-2030 edition | No amount recommended; no more than 10 g in one meal | Dietary Guidelines for Americans 2025-2030 |
| Energy per gram | Carbohydrate and protein 4, fat 9, alcohol 7 kcal | Dietary Guidelines 2015-2020, Chapter 1 |
| Weight-loss calorie patterns | 1,200 to 1,500 kcal for most women, 1,500 to 1,800 kcal for most men | Dietary Guidelines 2015-2020, Chapter 1 |
| Calories | 45% | 50% | 55% | 60% | 65% | Fibre ref. |
|---|---|---|---|---|---|---|
| 1,200 | 135 g | 150 g | 165 g | 180 g | 195 g | 17 g |
| 1,500 | 169 g | 188 g | 206 g | 225 g | 244 g | 21 g |
| 1,800 | 203 g | 225 g | 248 g | 270 g | 293 g | 25 g |
| 2,000 | 225 g | 250 g | 275 g | 300 g | 325 g | 28 g |
| 2,200 | 248 g | 275 g | 303 g | 330 g | 358 g | 31 g |
| 2,500 | 281 g | 313 g | 344 g | 375 g | 406 g | 35 g |
| 3,000 | 338 g | 375 g | 413 g | 450 g | 488 g | 42 g |
Many carb calculators take a few numbers and return one percentage. These are the details that change what the figure means.
| Feature | Basic carb calculator | This calculator |
|---|---|---|
| Results | Often needs a Calculate button | Updates as you type, with an answer on first load |
| Carbohydrate figure | One percentage, sometimes with no source | The sourced 45 to 65% range in grams, plus your own share inside it |
| Calorie formulas | One formula | Mifflin St Jeor, revised Harris-Benedict and Katch-McArdle |
| Weight-loss targets | Rarely any minimum | Deficit capped at 1,000 kcal a day and a floor from the US guidelines, said in words when it applies |
| Fibre and sugar | General text only | Fibre reference and added sugar limit in grams for your calories |
| Meals | Daily total only | Even split across 2 to 6 meals |
| Working and sources | Answer only, few links | Every step written out and every figure traced to a document |
| Units and sharing | Often one unit system | Metric and US units, copy the result or share a link |
If a plan lists carbohydrate as a percentage, enter your details and see what that percentage means in grams and in grams per meal.
The weight goal table shows the range for maintaining, losing and gaining side by side, so the effect of each calorie level is visible at once.
Labels list carbohydrate in grams. A daily range in grams gives those numbers something to be compared with.
Choose 2 to 6 meals to see an even split, then adjust by hand for training days, snacks or larger evening meals.
Pair the carbohydrate range with the protein calculator and the fat intake calculator, or use the macro calculator to split all three at once.
See how much energy an activity uses with the calories burned calculator next to your daily calorie estimate.
The numbers here are estimates built from published ranges. They describe typical adults, not any one person, and a doctor or registered dietitian decides what suits an individual.
The 45 to 65% figure is a range for adults, so 239 g and 345 g are both inside it for the default profile. The share you pick is only an input.
The same share gives more grams at a higher calorie level. Changing activity, weight goal or formula moves the result.
The revised Harris-Benedict equations estimate resting energy of normally nourished people with a precision of about 14%. Real needs differ from person to person.
The 2020-2025 edition said less than 10% of calories. The 2025-2030 edition says no amount is recommended and no more than 10 g in a meal.
The calculator counts total carbohydrate at 4 kcal per gram. It does not work out net carbs.
Nothing you type leaves your browser. After the page loads, the calculator keeps working without a connection.
It gives no result under 18 and cannot account for pregnancy, diabetes, kidney disease or any other condition. The 2025-2030 US guidelines say people with certain chronic diseases may do better on a lower carbohydrate diet and to work with a health care professional; see the Dietary Guidelines for Americans.
You can type any share, but the page does not label a share as low carb or keto, because no figure for that was taken from a source it lists. Shares outside 45 to 65% are marked as outside the published range.
The activity multipliers are a widely used convention, not a measured constant. The 7,700 kcal per kg weight rule is rough, and the meal split is equal. Athletes, older adults and people with a health condition may need a professional estimate.
The calculations are plain arithmetic on the published equations, checked against the worked examples and cross-page test cases. The reference values and equations come from these documents.
Short answers to common questions about daily carbohydrate grams.
There is no single amount. The US Dietary Guidelines appendix lists a range of 45 to 65 percent of daily calories for adults and a 130 g Recommended Dietary Allowance. At 2,000 calories that range is 225 to 325 g, and a doctor or registered dietitian can say what suits a particular person.
Multiply your daily calories by the carbohydrate share and divide by 4, because a gram of carbohydrate supplies about 4 kcal. For 2,000 kcal at 50 percent, that is 1,000 kcal divided by 4, which is 250 g.
AMDR stands for Acceptable Macronutrient Distribution Range. For carbohydrate in adults it is 45 to 65 percent of energy, as listed in Appendix 7 of the 2015-2020 Dietary Guidelines from the Dietary Reference Intakes.
The Recommended Dietary Allowance for carbohydrate is 130 g a day, and the same appendix lists it for adults and for children from age 1. This calculator tells you whether your figure is above or below 130 g and leaves the meaning to a health professional.
The fibre reference is about 14 g per 1,000 kcal, the basis of the Adequate Intake in the Dietary Guidelines appendix. At 2,000 kcal that is 28 g, and the calculator works it out for your own calories.
The 2020-2025 Dietary Guidelines said less than 10 percent of calories, about 50 g at 2,000 kcal. The 2025-2030 edition says no amount of added sugars is recommended and that one meal should contain no more than 10 g, so both are shown.
No. It counts total carbohydrate at 4 kcal per gram, the general factor the Dietary Guidelines use, and does not subtract fibre or sugar alcohols.
Pick 2 to 6 meals and the calculator divides your daily grams evenly. At the default 292 g over 3 meals that is about 97 g per meal, which you can adjust by hand for snacks or training.
Any share under 45 percent is below the published adult range, and the calculator says so next to the result. It does not define low carb or keto, because no figure for that comes from a source on this page. The 2025-2030 Dietary Guidelines say some people with chronic disease may do better on a lower carbohydrate diet and to work with a health care professional.
The default is Mifflin St Jeor, with revised Harris-Benedict and Katch-McArdle as options. Katch-McArdle needs a body fat percentage. For a 30 year old woman at 165 cm and 65 kg, moderately active, Mifflin gives a BMR of 1,370 and maintenance of 2,124 kcal.
The 2015-2020 Dietary Guidelines describe eating patterns of 1,200 to 1,500 kcal for most women and 1,500 to 1,800 kcal for most men for weight loss. The calculator will not apply a weight-loss deficit that takes the target below 1,200 for women or 1,500 for men, and it caps any deficit at 1,000 kcal a day. It says so in words whenever either limit applies.
No. The calculation runs in your browser and nothing is sent to a server. Your numbers appear in the page address only so a shared link opens with the same values, and your unit choice is remembered on your own device.