Ideal Weight & Macro Calculator
See your ideal body weight range from four standard formulas, plus a daily protein, carb, and fat split for your calorie goal. Enter your details and results update as you type — nothing is uploaded.
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Fill in your details to see your ideal weight range.
Daily plan
This is for general information only and is not medical or nutritional advice — talk to your doctor or a dietitian. Ideal-weight formulas and macro splits are averages that ignore muscle, body composition, and individual needs, and do not apply to children or teens.
How to use the ideal weight & macro calculator
Choose your units, then enter your age, sex, and height. Your ideal body weight range appears instantly from four standard formulas. Add your weight and activity level — and pick a goal — to also see a daily protein, carb, and fat split. There's no button to press and nothing is sent anywhere.
Why a range, not one number. Ideal-weight formulas disagree by a few kilograms because they were derived differently, so a range across all four is more honest than a single figure.
Everything runs in your browser — the numbers you type are never uploaded.
The four ideal-weight formulas
Each formula gives a reference weight for your height and sex. Three are linear in inches over 5 feet; Hamwi is the classic imperial rule:
- Devine (1974): 50 kg (men) / 45.5 kg (women) + 2.3 kg per inch over 5 ft
- Robinson (1983): 52 kg (men) / 49 kg (women), +1.9 / +1.7 kg per inch over 5 ft
- Miller (1983): 56.2 kg (men) / 53.1 kg (women), +1.41 / +1.36 kg per inch over 5 ft
- Hamwi (1964): 48 kg (men) / 45.5 kg (women), +2.7 / +2.2 kg per inch over 5 ft
How the macros are worked out
The calculator estimates your Total Daily Energy Expenditure (TDEE) from the Mifflin–St Jeor equation and a standard activity factor — or, if you enter your body-fat percentage, the more precise Katch-McArdle equation based on lean mass. It adjusts that for your goal (about 20% below maintenance to lose fat, 10% above to gain muscle), then builds the plate in the order the evidence supports:
- Protein by bodyweight, not by percentage. Roughly 1.6 g/kg at maintenance, rising to 1.8–2.4 g/kg when you're losing fat or training hard (per the ISSN position stand and Morton 2018 meta-analysis). A flat percentage gets this backwards — it raises protein when you eat more and cuts it when you eat less, the opposite of what protects muscle on a diet.
- Fat with a floor. About 30% of calories by default, but never below 0.8 g/kg, which protects hormone health.
- Carbohydrate fills the rest of your calorie target.
Grams come from the standard energy values: 4 calories per gram for protein and carbohydrate, 9 for fat. The tool also estimates a fiber target (14 g per 1,000 calories) and a water target (about 35 ml per kg of bodyweight). The diet-style presets shift only the carb-to-fat balance; keto pins carbs low and lets fat fill the gap.
Common questions
What is ideal body weight? A reference weight for your height. There's no single right value, so this tool shows a range across four formulas.
Which formula is best? None definitively — Devine is the most used clinically. The range, compared with a healthy BMI, is more useful than any one number.
What is a good macro split? Set protein by your bodyweight (about 1.6 g/kg to maintain, more when cutting or training hard), keep fat at or above 0.8 g/kg, and let carbs take the rest. Raise protein if you're dieting; the presets here only move the carb-to-fat balance. Treat it as a starting point.
This calculator is for general information only and is not medical or nutritional advice. Talk to your doctor or a registered dietitian before making big changes.