Target Weight by BMI Calculator
Find the body weight that matches a chosen BMI for your height, your healthy-weight range (standard or Asian cut-offs), how much you would need to lose or gain from your current weight, and how long that takes at a steady weekly pace.
How it works
Target weight = target BMI × height(m)² · Healthy range = 18.5 to 24.9 × height(m)² (18.5 to 22.9 with Asian cut-offs) · Change = target weight − current weight · Weeks = change ÷ weekly pace · Daily calories ≈ weekly pace (kg) × 7,700 ÷ 7
Body mass index is weight in kilograms divided by height in metres squared, so turning it around gives the weight that matches any BMI at your height. Pick a target BMI (22 sits near the middle of the healthy band) and the calculator returns the matching weight, the whole healthy-weight range and the BMI category your target falls in. Enter your height in centimetres, inches or metres. If you also enter your current weight (kg, lb or stone), you see your current BMI and category, how much you would need to lose or gain, and how far you are from the edge of the healthy range. Under More options, a weekly pace turns that into a timeline and a rough daily calorie deficit or surplus, using the common estimate that 1 kg of body weight holds about 7,700 kcal. Real weight loss is rarely a straight line, so treat the timeline as a guide. The Asian cut-offs follow the WHO expert consultation and UK NICE guidance, which use 23 and 27.5 as the overweight and obesity thresholds for people of Asian, Black African and African-Caribbean background. BMI is a population screening tool: it does not tell muscle from fat, so athletes and some body types are misclassified.
Worked example
For a height of 170 cm (1.70 m), height squared is 2.89 m². A target BMI of 22 gives 22 × 2.89 ≈ 63.6 kg (140.2 lb). The healthy range spans 18.5 × 2.89 ≈ 53.5 kg up to 24.9 × 2.89 ≈ 72.0 kg. Someone weighing 75 kg at that height has a BMI of 75 ÷ 2.89 ≈ 26.0 (overweight) and would need to lose about 11.4 kg to reach the target, or 3.0 kg to reach the top of the healthy range. At 0.5 kg a week, that takes about 23 weeks, with a daily deficit of about 550 kcal. With the Asian cut-offs, the healthy range ends at 22.9 × 2.89 ≈ 66.2 kg.
Sources: WHO — Body mass index · WHO Expert Consultation (2004), Appropriate body-mass index for Asian populations, The Lancet · NICE — BMI: preventing ill health and premature death in Black, Asian and other minority ethnic groups (PH46) · CDC — Adult BMI categories
Frequently asked questions
What BMI should I target?
A BMI of 18.5–24.9 is classed as healthy for most adults, and many people aim near the middle, around 21–23. There is no single ideal number: the healthiest weight depends on your body composition, health markers and history, so treat any target as a guide rather than a rule. If you have a lot to lose, the top of the healthy range, or even a 5–10% loss, is a sensible first milestone.
Why are there Asian cut-offs?
Studies show that people of Asian background tend to have more body fat and a higher risk of type 2 diabetes and heart disease at the same BMI. The WHO and UK NICE therefore suggest 23 for overweight and 27.5 for obesity in these groups, and NICE applies the same thresholds to people of Black African and African-Caribbean background. Choose Asian cut-offs to see the narrower healthy range.
How long will it take to reach my target weight?
Enter your current weight and a weekly pace under More options. The calculator divides the difference by the pace, so 10 kg at 0.5 kg a week is 20 weeks. Weight loss usually slows over time, so the real timeline is often longer. A pace of about 0.25–1 kg (0.5–2 lb) a week is the usual advice.
Is BMI accurate for everyone?
No. Because it uses only height and weight, BMI over-reads for very muscular people and can under-read for those with low muscle mass. It also does not account for fat distribution, age or ethnicity, so it is a screening estimate, not a diagnosis. A waist measurement adds useful information.
How is this different from an ideal-weight formula?
This tool works purely from a BMI target and your height. Ideal-weight formulas (such as Devine or Robinson) use different equations and frame size, and often give a slightly different number. Comparing both can give you a sensible range to aim within.
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Educational estimate only — not medical advice, and not a substitute for a clinician, pharmacist or product label. Dosing, fluid and kidney decisions must be confirmed by a qualified professional using the actual drug, patient and situation. Do not use this tool to self-treat.