TDEE Calculator
Estimate BMR (basal metabolic rate) and TDEE (total daily energy expenditure) using the Mifflin-St Jeor equation and a standard activity multiplier.
Tool description
TDEE is an estimate of how many calories you burn per day based on your BMR and an activity multiplier. This tool uses the Mifflin-St Jeor equation (widely used in nutrition planning) plus standard activity factors.
How to use
- Enter your sex, age, height, and weight.
- Select an activity level that matches your typical week.
- Calculate to see estimated BMR and TDEE.
- Use TDEE as a starting point for calorie targets (adjust based on results over time).
Why it’s useful
- Set a baseline for weight loss, maintenance, or gain planning.
- Compare scenarios by adjusting activity level.
- Pair with macro or calorie deficit planning tools.
Use cases & interpretation
- Weight loss: a deficit below TDEE may reduce weight over time.
- Maintenance: eating near TDEE tends to maintain weight (on average).
- Muscle gain: a small surplus above TDEE may support gaining weight.
Deep dive: TDEE Calculator
TDEE Calculator is designed to be fast, readable, and practical: you enter a few inputs, the tool shows a clear result, and you can copy or reset in one click.
This page focuses on the “why” and the “how”: what the calculator or converter is doing, which assumptions matter, and how to interpret the output so you can make a better decision.
How it works
Health calculators are best for estimates and trends, not diagnoses. Most formulas were designed as population-level approximations and can be wrong for individuals.
The biggest improvement you can make is consistency: measure the same way, at the same time of day, and compare weekly trends rather than single readings.
TDEE (Total Daily Energy Expenditure) estimates how many calories you burn per day. Calculators usually combine a base metabolic equation with an activity multiplier.
Privacy note: Smart Web Apps runs tools in your browser whenever possible. We don’t require accounts, and we don’t ask you to upload sensitive inputs for most tools.
Why it’s useful
- Set a baseline and track direction over time.
- Convert goals into numbers you can plan (calories, macros, hydration).
- Understand what a metric means and what it doesn’t.
Practical tips (better results)
- Treat outputs as ranges (estimates), not exact values.
- If you change your plan, change one variable at a time and observe for 2–4 weeks.
- If you have symptoms or a medical condition, use professional guidance first.
How to sanity-check results: first, try a small input where you can predict the direction (increase an input and confirm the output changes in the expected way). Next, do a quick reverse check when possible (for example, convert there and back, or compare a rate and its inverse). Finally, compare a simplified manual calculation (a single bracket slice, a single unit conversion factor, or a single time interval) to confirm the tool’s logic matches your expectations.
Rounding and formatting matter more than most people expect. Real-world receipts, payroll systems, and financial statements often round at specific steps (line items vs totals). If your result differs by a small amount, it may be a rounding rule rather than a “wrong” calculation. When you share the output, include the rounding assumption (for example, “rounded to 2 decimals”) so the result is reproducible.
Troubleshooting tip: if you see an error, double-check the input format first (commas vs dots, spaces, percent symbols, or mixed units). Then reset and re-enter values slowly. If the tool depends on a public data source, check your connection and any script/privacy blockers that might block requests. When reporting an issue, include the page URL, your browser, and a small example input that reproduces the behavior.
Best practice for planning: treat single-number outputs as an estimate, then run a second scenario that is deliberately conservative (slightly worse assumptions). If your decision still works under conservative inputs, you’re far less likely to be surprised.
When you use TDEE Calculator for communication (a quote, a ticket, or a study plan), write one sentence that explains the context: what the inputs represent, what is included, and what is excluded. This prevents misinterpretation—especially for calculators where “taxable income”, “APR”, “workdays”, or “usable hosts” have specific meanings.