Macro Calculator
Split your calorie target into protein, carbohydrate and fat grams.
About Macro Calculator
Calories from protein and carbohydrates provide 4 kcal per gram, while fat provides 9 kcal per gram. Each diet style allocates a different percentage of your calories to each macronutrient, which we convert into grams.
Formulas
Protein and carbohydrates
Grams = total calories × macro % ÷ 4 (protein & carbs yield 4 kcal/g)
- 4
- Calories per gram of protein or carbohydrate
- g
- Grams of the macronutrient
- C
- Daily calorie target
- p%
- Fraction of calories allocated to this macro
Fat
Fat grams = total calories × fat % ÷ 9 (fat yields 9 kcal/g)
- 9
- Calories per gram of fat
- g_fat
- Grams of fat
- C
- Daily calorie target
- f%
- Fraction of calories allocated to fat
Worked example
With the default values below, Macro Calculator returns Protein (g/day) of 165. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Daily Caloriesaccepts 800–6,000 kcal
- 2,200 kcal
- Diet Styleone of Balanced (30/40/30), Low Carb (40/20/40), High Protein (40/35/25), Keto (25/5/70)
- Balanced (30/40/30)
Results
- Protein (g/day)
- 165
- Carbs (g/day)
- 220
- Fat (g/day)
- 73
Step by step
- 1Calorie target and macro percentages
- 2Protein: calories × % ÷ 4 kcal/g= 165 g
- 3Carbohydrates: calories × % ÷ 4 kcal/g= 220 g
- 4Fat: calories × % ÷ 9 kcal/g= 73 gFat has 9 kcal/g versus 4 kcal/g for protein and carbs.
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- This is an estimate and not medical or nutritional advice. Macronutrient needs depend on individual health goals and conditions. Consult a registered dietitian for personalised recommendations.
- This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Macro Calculator — full guide
Turning a calorie target into food
A calorie target tells you how much to eat; macros tell you what. Food labels and nutrition apps report grams, so a plan expressed in percentages of calories has to be converted before it is usable. That conversion is the whole job of this page.
Energy density
Protein and carbohydrate release about 4 kcal per gram, fat about 9. So:
Grams = calories × macro % ÷ 4 for protein and carbohydrate
Fat grams = calories × fat % ÷ 9
The percentages come from the diet style you pick, and each preset allocates all 100% of your calories:
| Diet style | Protein | Carbs | Fat |
|---|---|---|---|
| Balanced | 30% | 40% | 30% |
| Low Carb | 40% | 20% | 40% |
| High Protein | 40% | 35% | 25% |
| Keto | 25% | 5% | 70% |
Worked example
A 2,200 kcal target on the balanced preset:
- Protein:
2,200 × 0.30 = 660kcal, then660 ÷ 4 = 165g - Carbohydrate:
2,200 × 0.40 = 880kcal, then880 ÷ 4 = 220g - Fat:
2,200 × 0.30 = 660kcal, then660 ÷ 9 = 73g
Adding the calories back gives 660 + 880 + 660 = 2,200, which is the check that the split is consistent.
The same calories, keto split
At 25/5/70 the same 2,200 kcal becomes 138 g protein, 28 g carbohydrate and 171 g fat. Fat grams jump from 73 to 171 while carbohydrate grams fall by nearly 200 — identical energy, a completely different shopping list.
Reading the grams
Protein and fat are the numbers to anchor on; carbohydrate tends to fill whatever space is left. Note that equal percentages do not mean equal grams: 30% protein gives 165 g but 30% fat gives only 73 g, purely because of the 4-versus-9 divisor. People often read the small fat number as a mistake.
Common slips
- The percentages are shares of calories, not shares of grams. The grams will never be in a 30/40/30 ratio.
- Hitting the exact figures daily is unnecessary; being within 5–10 g is fine in practice.
- Protein scaled to body weight is the usual sanity check: 165 g is about 1.9 g per kg for an 85 kg person, and closer to 2.4 g/kg at 70 kg.
- Change the calorie target and every gram figure changes with it, so set calories first.
- These splits are starting points, not nutritional or medical advice — a registered dietitian should set targets around diabetes, kidney disease or pregnancy.
Set the calorie figure with the calorie calculator, check the resting baseline on the BMR calculator, and plan fluids with the water intake calculator.
This is an estimate and not medical or nutritional advice. Macronutrient needs depend on individual health goals and conditions. Consult a registered dietitian for personalised recommendations.
Frequently Asked Questions
How much protein do I need?
Active individuals often target around 1.6–2.2 g of protein per kg of body weight. The preset percentages here are a starting point you can adjust with a dietitian.
Which diet style is best?
The best split is the one you can sustain while meeting your goals. Balanced works for most people; lower-carb or keto suit specific preferences and medical guidance.
The keto preset gives me under 30 g of carbs — is that figure right?
It is. Keto allocates 5% of calories to carbohydrate, so at 2,200 kcal that is 110 kcal, and 110 ÷ 4 gives 27.5 g, displayed as 28 g. A single banana is around 27 g of carbohydrate, which shows how tight that allowance is and why the preset suits only people committed to the approach.
Why is my fat target in grams so much smaller than my carb target?
Because fat packs 9 kcal into each gram against 4 for carbohydrate. On the balanced preset at 2,200 kcal both get 30% and 40% of calories respectively — 660 and 880 kcal — but dividing by 9 rather than 4 turns that into 73 g of fat against 220 g of carbs. Small gram numbers, large energy contribution.
Do the three gram totals add back up to the calories I entered?
They should, within rounding. Take the balanced 2,200 kcal result: 165 g × 4 = 660, 220 g × 4 = 880, and 73.3 g × 9 = 660, which sums to 2,200 kcal. If you round each gram figure before multiplying you will land a few calories off — that is display rounding, not an error in the split.
What if the preset protein figure looks too high for my size?
Check it against body weight. The balanced preset at 2,200 kcal gives 165 g, which is 2.4 g per kg at 70 kg — above the 1.6–2.2 g/kg range most active people work in. Either raise the calorie target or move some protein percentage into carbohydrate by choosing a different style.