Energy Balance Calculator

About this calculator

Energy balance is the foundational principle behind weight change, often summarized as CICO — Calories In, Calories Out. It compares the calories you consume against the calories your body burns (your total daily energy expenditure, or TDEE, which includes your resting metabolism, digestion, and physical activity); the difference between the two is your daily balance, either a surplus (more in than out) or a deficit (more out than in).

Using the same rule of thumb that roughly 7,700 kcal equals about 1 kg of body weight (or 3,500 kcal per pound), a steady daily surplus or deficit can be projected forward to estimate the weight gain or loss expected over a week or longer, assuming the balance stays consistent.

This is the core calculation behind virtually every nutrition coaching program and fitness tracking app, since regardless of diet philosophy — keto, intermittent fasting, high-protein, or anything else — weight change ultimately comes down to whether you're in a calorie surplus or deficit over time; this calculator makes that number and its projected effect visible directly.