Estimate your calories, then see the published fat range in grams a day, a saturated fat limit and a per-meal split.
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.
Slide to any point inside the published range.
| Meals | Total fat each | Saturated, up to |
|---|
| Goal | Calories | Total fat | Sat. fat |
|---|
Private by design. Everything runs in your browser and is never uploaded. Results are estimates.
A fat intake calculator estimates how many grams of fat a day fit inside a published guideline. For adults the Dietary Reference Intake range is 20 to 35 percent of daily calories from fat, and each gram of fat has 9 calories. This calculator estimates your calories first, then converts that range to grams a day and per meal.
The range comes from the Dietary Reference Intake tables, and the saturated fat limit from the Dietary Guidelines for Americans 2025 to 2030. If you do not know your calories yet, start with the calorie calculator or the TDEE calculator, or let this page estimate them from your age, height, weight and activity. Results update as you type and the working shows every step. For other everyday sums, see the free online calculators.
| Example | Calories | Total fat | Saturated, up to |
|---|---|---|---|
| Woman, 30 y, 165 cm, 65 kg, moderately active, Mifflin-St Jeor | 2,124 | 47 to 83 | 24 |
| Man, 30 y, 180 cm, 80 kg, moderately active, Mifflin-St Jeor | 2,759 | 61 to 107 | 31 |
| Same man, revised Harris-Benedict | 2,873 | 64 to 112 | 32 |
| Same woman, lose 0.5 kg a week (550 kcal a day less) | 1,574 | 35 to 61 | 17 |
| Same woman, lose 1 kg a week: deficit capped at 1,000, target 1,124 raised to the 1,200 minimum | 1,200 | 27 to 47 | 13 |
| Calories typed in as 2,000 | 2,000 | 44 to 78 | 22 |
The first answer is already on screen. Change any number and it updates at once, with no Calculate button.
Pick female or male, metric or US units, then type age (18 to 100), weight, height and an activity level. If you already have a calorie number, tap I know my calories and type it instead.
Keep Maintain weight, or pick a loss or gain per week. The calculator applies a rough rule of thumb, caps the daily deficit and never shows a target below the minimum it cites.
Total fat appears as a range in grams, with the saturated fat limit and a per-meal split. Slide the marker to see your own point inside the range.
Open the working to see every conversion, formula and rounding step. Copy the result, or share a link that opens with the same numbers.
There are four steps. The calculator estimates your resting energy use (BMR) with the Mifflin-St Jeor equation from the 1990 paper by Mifflin and colleagues, or with revised Harris-Benedict or Katch-McArdle if you pick them. It multiplies by an activity factor to get total daily energy expenditure (TDEE), and a weight goal then adds or removes calories. Last, the fat share of those calories is turned into grams at 9 calories per gram.
The paper prints the weight and age coefficients as 9.99 and 4.92. The rounded 10 and 5 used here is the form in wide use and differs by about 10 calories or less for typical adults. The five activity factors are a common convention, not measured values, and we could not trace them to one primary source. For a fuller look at BMR and TDEE, see the TDEE calculator.
| Value | Formula |
|---|---|
| BMR, Mifflin-St Jeor | Men: 10 × kg + 6.25 × cm − 5 × age + 5. Women: 10 × kg + 6.25 × cm − 5 × age − 161 |
| BMR, revised Harris-Benedict | Men: 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age. Women: 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age |
| BMR, Katch-McArdle | 370 + 21.6 × lean body mass in kg, where lean mass = weight × (1 − body fat % ÷ 100) |
| TDEE | BMR × activity factor |
| Goal target | TDEE ± rate × 7,700 ÷ 7 per kg (3,500 per lb), deficit capped at 1,000, never below 1,200 (women) or 1,500 (men) |
| Total fat | Calories × 20% to 35% ÷ 9 (25% to 35% at age 18) |
| Saturated fat | Calories × 10% ÷ 9, as an upper limit |
| Per meal | Grams ÷ number of meals |
| Level | Factor | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise |
| Lightly active | 1.375 | Light exercise 1 to 3 days a week |
| Moderately active | 1.55 | Exercise 3 to 5 days a week |
| Very active | 1.725 | Exercise 6 to 7 days a week |
| Extra active | 1.9 | Hard daily exercise plus a physical job, or two sessions a day |
Total fat at 20% and 35% of calories, and the saturated fat limit at 10%, in grams a day. Whole grams, halves rounded up.
| Calories a day | Fat at 20% | Fat at 35% | Saturated fat, up to 10% |
|---|---|---|---|
| 1,200 | 27 | 47 | 13 |
| 1,400 | 31 | 54 | 16 |
| 1,500 | 33 | 58 | 17 |
| 1,600 | 36 | 62 | 18 |
| 1,800 | 40 | 70 | 20 |
| 2,000 | 44 | 78 | 22 |
| 2,200 | 49 | 86 | 24 |
| 2,400 | 53 | 93 | 27 |
| 2,500 | 56 | 97 | 28 |
| 2,600 | 58 | 101 | 29 |
| 2,800 | 62 | 109 | 31 |
| 3,000 | 67 | 117 | 33 |
| 3,500 | 78 | 136 | 39 |
Each row is calories × the percentage ÷ 9. At 18 the published range is 25% to 35%, so the low end is higher; the calculator above handles that.
Many fat calculators ask for calories and a percentage and stop at one gram figure. These are the details that change how far you can trust a number.
| Feature | Basic fat calculator | This calculator |
|---|---|---|
| Result | One gram figure, often with no stated percentage | A range in grams for 20% to 35% of calories, plus your own point inside it |
| Calories | A typed number, or one unnamed formula | Three named formulas with their sources, or calories you type in |
| Working | Answer only | Every conversion, formula and rounding step written out |
| Saturated fat | Missing, or without a source | Up to 10% of calories, from the Dietary Guidelines, per day and per meal |
| Per meal | Rarely offered | An even split for 2 to 6 meals |
| Weight goals | Often no safeguards | Deficit capped at 1,000 calories, minimum targets stated in words next to the number |
| Age | Often ignored | Adults only; the 25% to 35% row is used at age 18 |
| Units | One system | Metric and US, with the conversions shown |
| Sharing | Rare | Copy the result or share a link with the same numbers |
If a dietitian or an app gave you a calorie number, tap I know my calories to see what 20% to 35% of it looks like in grams.
Labels list fat in grams, so a range in grams is easier to compare with a food label than a percentage of calories.
The goals table shows the calories, fat range and saturated fat limit for every goal at once, with any minimum applied.
The per-meal table splits the day into 2 to 6 meals. Pair it with the protein calculator and the carbohydrate calculator, or see all three together in the macro calculator.
Switch between Mifflin-St Jeor, revised Harris-Benedict and Katch-McArdle to see how far the calories, and the grams, move.
If you train, estimate what a session uses with the calories burned calculator and compare it with your activity level here.
The numbers here describe published guidelines. They are not a prescription, and a doctor or registered dietitian can say what suits a particular person.
An acceptable macronutrient distribution range is described as the range of intakes linked to a reduced risk of chronic disease while still providing adequate essential nutrients. Anywhere inside 20% to 35% is within the published range.
Because the range is a share of energy, the grams rise and fall with the calories. The same percentage gives more grams at 2,800 calories than at 1,800.
Fat carries 9 calories a gram against 4 for protein and carbohydrate, so a few grams of fat change the calorie total quickly.
This page covers total fat and the saturated fat limit. The Dietary Guidelines themselves note that more research is needed on which types of fat best support long-term health.
The reference table gives 25% to 35% for ages 4 to 18 and 20% to 35% from 19. The calculator uses the first row at 18 and says so.
The 7,700 calories per kg (3,500 per lb) rule is a rule of thumb. NIH researchers describe it as too simplistic because the body adjusts to a calorie deficit.
BMR equations predict resting energy from group data, and the activity factors are conventions. Two people with the same inputs can differ by hundreds of calories in real life.
It is built for healthy adults aged 18 and over. A doctor or dietitian can give figures that fit a medical condition, pregnancy, breastfeeding or a prescribed diet. Under 18 it shows a note instead of a result.
It does not break fat into types, count trans fat or omega-3, or suggest foods. For protein and carbohydrate ranges, use the macro calculator.
Every figure here comes from a page we opened. The list says what each page supports.
Not traced to a primary source: the five activity factors (a widely used convention). The rounded Mifflin-St Jeor form, the revised Harris-Benedict coefficients and the Katch-McArdle formula were checked against Wikipedia and against test cases, not against the original papers and textbook.
Short answers to common questions about daily fat, saturated fat and how the numbers are worked out.
A published reference range for adults is 20 to 35 percent of daily calories from fat. At 2,000 calories that is 44 to 78 grams a day. This calculator shows the range for your own estimated calories, and a doctor or dietitian can say what suits you.
Multiply your daily calories by the fat percentage, then divide by 9, because the Atwater general factor for fat is 9 kilocalories per gram (4 for protein and carbohydrate, 7 for alcohol). For 2,000 calories at 30 percent, 2,000 × 0.30 = 600 calories from fat, and 600 ÷ 9 = 67 grams.
The Dietary Guidelines for Americans 2025 to 2030 say saturated fat should not exceed 10 percent of total daily calories. At 2,000 calories that is 200 calories, or about 22 grams a day. The calculator shows this limit for your own calories and per meal.
The Dietary Reference Intake tables list no recommended daily amount for total fat in adults. They give an acceptable range of 20 to 35 percent of energy instead, which is the range this calculator uses.
The same Dietary Reference Intake table has one row for ages 4 to 18, at 25 to 35 percent of energy, and another for ages 19 and over, at 20 to 35 percent. The calculator switches rows at age 19.
The percentage stays the same, but the calorie target changes, so the grams change too. A lower target gives fewer grams. The goals table shows the range for every goal side by side.
The calculator raises it to 1,200 calories for women or 1,500 for men, the minimums Harvard Health cites, and says so in words next to the number. It also caps any daily deficit at 1,000 calories and warns when a target is below your estimated resting energy use.
Mifflin-St Jeor is the default. Revised Harris-Benedict and Katch-McArdle (which needs a body fat percentage) are options. The 1990 Mifflin paper reported that the original 1919 Harris-Benedict equations overestimated measured resting energy expenditure by about 5 percent in its sample.
Divide the grams by the number of meals; the per-meal table does this for 2 to 6 meals. An even split is simple arithmetic for planning, and the published range describes the whole day, not each meal.
Results differ with the calorie formula, the activity multiplier, the fat percentage and the calories per gram. This page shows every step so you can compare, and it uses 9 calories per gram.
No. It is for adults aged 18 and over. Under 18 it shows a note and suggests asking a doctor or school nurse about the amounts that suit the person.
No. The calculation runs in your browser and nothing is sent to a server. Your numbers appear in the page address only when you copy a share link, and your metric or US choice is remembered on your own device.