See how far your weight sits above a healthy range and what it takes to return.
This calculator quantifies how much weight is above the upper healthy BMI boundary (24.9 kg/m²) and converts that into an actionable goal: how long it will take to reach a healthy range at a chosen weekly loss rate. One kilogram of body fat stores approximately 7,700 kcal, so losing 0.5 kg/week requires a sustained 550 kcal/day deficit.
Excess weight
Excess weight = Current weight − (24.9 × height² in m²)
BMI is a screening tool, not a clinical diagnosis. Results are estimates — individual metabolic rate, body composition, and health history affect actual outcomes. This is not medical advice.
Mild overweight (BMI 25–27) carries only modestly elevated risk. Risk increases more steeply from BMI 30 onwards. The J-shaped mortality curve also shows that very low BMI (<20) is associated with elevated risk, so the goal is to be in the healthy range, not as light as possible.
0.5–1 kg/week is the range most evidence supports as sustainable without excessive lean mass loss. Faster rates are sometimes appropriate under medical supervision, but below-VLCD deficits (>1000 kcal/day) accelerate muscle loss and metabolic slowdown.
A kilogram of adipose tissue contains roughly 7,700 kcal of stored energy. In practice, early weight loss includes more glycogen and water; pure fat loss only yields this rate at steady state. Real-world results are typically 70–85% of what the formula predicts.