Everything you might be wondering, in plain English.
TDEE stands for Total Daily Energy Expenditure. It's the total number of calories you burn in a day - everything from your base metabolism and digesting food to walking, working out, and even fidgeting. It's the number you need to eat to stay the same weight.
BMR (Basal Metabolic Rate) is the calories you'd burn if you lay completely still all day. TDEE is your BMR multiplied by an activity factor to reflect real life. TDEE is the useful number for planning weight loss, gain, or maintenance.
By default, we use the Mifflin-St Jeor equation - it's the most accurate for the general population. If you enter a body fat percentage, we switch to the Katch-McArdle formula, which is more accurate for people who carry more muscle or more fat than average.
It's an estimate, not a measurement. Formulas like Mifflin-St Jeor typically land within 10% for most people. The best approach is to use the number as a starting point, track your weight for 2-3 weeks, then adjust up or down based on what actually happens.
Leave it blank. The calculator falls back to Mifflin-St Jeor, which only needs age, height, weight, and gender. That's accurate enough for most people. If you want a body fat estimate, try the Body Fat Estimator - it uses the Navy tape method with just a few measurements.
A deficit of 10-20% below your TDEE is generally recommended - that's roughly 0.5-1% of body weight lost per week. Faster than that usually means losing muscle and feeling rubbish. The Cutting preset uses a 20% deficit and Mild loss uses 10%.
A surplus of 10-20% above TDEE is standard. The Mild gain preset (10%) is a good default for a slow, controlled bulk. The Gain preset (20%) is more aggressive and works well when you're new to lifting or trying to add size quickly.
Usually no. Your activity multiplier already accounts for typical exercise. Only add extra food on days with unusually long or intense sessions - a multi-hour hike, a race, or similar.
It depends on your preference and goal. All three splits show protein / carbs / fat percentages. Balanced (30/35/35) is a solid all-rounder and a good default. Low Carb (30/20/50) cuts carbs and increases fat - useful if you find higher-carb diets leave you hungry, or if you prefer a lower-carb approach. High Protein (40/40/20) is high in both protein and carbs, which suits people training hard who want to prioritise both muscle retention and fuel.
At higher body weights, some tools give lower estimates by using adjusted body weight instead of actual weight. Both approaches are within normal variance - use this as a starting point and adjust based on real-world results.
The Navy tape method is typically accurate to within 3-4% compared with DEXA scanning, which is the clinical gold standard. The key to reliability is consistency - measure the same spots, with the same tension on the tape, ideally at the same time of day. Track the trend over weeks rather than obsessing over a single reading.
Completely free. No signup, no email, no account. All calculations run in your browser - nothing you enter is sent to a server or stored anywhere. Basic anonymous analytics tell me how many people are using the site, but nothing about you personally.
The current line-up includes the TDEE Calculator, BMI Calculator, Macro Calculator, Calorie Deficit Planner and Body Fat Estimator. Future tools will be based on what users actually find useful, so if there's something you'd like to see, get in touch.
Please do! Just send them the main link - everything is free and there's nothing to sign up for.