IIFYM calculator
IIFYM means “if it fits your macros” — flexible dieting where you hit daily protein, fat and carb targets and eat whatever foods you like to get there. Get your numbers below, then build meals that fit them. Free, runs in your browser, no signup.
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Takes about 20 seconds.
≈ 2,630 cal · 135g protein · 75g fat · 355g carbs to maintain weight.
This is an estimate, not medical advice.
What is IIFYM?
IIFYM, short for if it fits your macros, is a flexible way to diet. Rather than following a fixed list of “allowed” and “banned” foods, you set targets for the three macronutrients — protein, fat and carbs — and then eat any foods you like, as long as the day adds up to those numbers. No food is off-limits on its own; what drives your results is the totals.
It rests on a simple truth: your body responds to the calories and macros you eat, not to whether a food is labelled “clean.” That is also why no single macro is “bad”. New to the three numbers themselves? Start with what macros are.
How to do IIFYM well
The flexibility is the point, but the people who get the best results use it sensibly. Hit your proteintarget first, since it protects muscle and keeps you full. Build most of your meals from whole, nutritious foods because they fill you up for fewer calories — then fit in the treats you enjoy with whatever room is left. IIFYM isn’t a license to eat only junk; it’s permission not to feel guilty about a treat that fits.
You also only really need to track your macros, not calories on top: hitting your protein, fat and carb grams lands your calories automatically. If you want the arithmetic, how to calculate your macros covers it.
Now make foods fit your macros
The hard part of IIFYM is the daily puzzle of making real food fit your remaining numbers. That’s exactly what the rest of the tool does. Calculate above, then let the Adviser rank foods and meals that fit what you have left, or give the Solver the foods you want and get the exact grams.
Common questions
- What is IIFYM?
- IIFYM stands for 'if it fits your macros'. It is a flexible approach to dieting where, instead of following a rigid list of allowed foods, you set daily targets for protein, fat and carbs and then eat any foods you like as long as they fit those numbers. The idea is that no single food is off-limits — what matters for your results is the totals you hit across the day.
- How does an IIFYM calculator work?
- It estimates the calories you burn in a day from your age, height, weight, sex and activity, adjusts that for your goal — a moderate deficit to lose, a surplus to gain — and then splits the calories into grams of protein, fat and carbs. Those three numbers are your macros. Hit them with whatever foods you choose and you are doing IIFYM.
- Can you eat junk food on IIFYM?
- In principle yes, as long as it fits within your macros for the day — that flexibility is the whole point. In practice, most people aim to get the majority of their calories from whole, nutritious foods because they are more filling and better for health, then fit in treats with whatever room is left. IIFYM is not a license to eat only junk; it is permission not to feel guilty about a treat that fits.
- Is IIFYM good for weight loss?
- Yes. IIFYM is just calorie and macro control with built-in flexibility, and that flexibility is exactly what makes it easier to stick to than restrictive diets. As long as your targets put you in a calorie deficit and you hit your protein, you will lose fat while still being able to eat foods you enjoy, which is what keeps most people consistent enough to see results.
- Do I count calories or macros on IIFYM?
- Macros. Because protein and carbs carry about 4 calories per gram and fat about 9, hitting your protein, fat and carb targets automatically lands you on your calorie total — so counting calories on top is double-bookkeeping. Track the three macro numbers and your calories take care of themselves.
This calculator gives general estimates for healthy adults and is not medical or nutritional advice. If you have a medical condition or are pregnant, talk to a professional before changing how you eat.