Bulking Calorie Calculator
Set a calorie surplus for muscle gain, sized to add mass without unnecessary fat.
Why a small surplus beats a large one
Muscle accrues at roughly 0.25–0.5 kg a month for a trained lifter, and no surplus makes it faster — it only makes the accompanying fat gain larger. A 250–350 kcal surplus supplies what tissue synthesis needs with little left over. Anything beyond that is a decision to diet later.
The formula
Mifflin-St Jeor: BMR = 10·weight(kg) + 6.25·height(cm) − 5·age + s, where s is +5 for men and −161 for women.
Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.
How to use the Bulking Calorie Calculator
- Fill in each field with your own figures — the defaults are only there as an example.
- The result updates as you type, so there is no button to press.
- Check the breakdown under the main result for the supporting numbers.
- Use the copy button to take the result with you, or share the link to reload the same inputs.
Bulking Calorie Calculator — frequently asked questions
How big should a calorie deficit be?
A deficit of about 500 kcal per day produces roughly 0.5 kg (1 lb) of weight loss per week for most people. Deficits beyond 1000 kcal per day are hard to sustain and risk losing muscle.
Why do two people of the same weight need different calories?
Height, age, sex and lean mass all change basal metabolic rate, and daily activity can vary by more than 1000 kcal between a desk worker and a manual worker.
Is this bulking calorie calculator free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
How accurate is the result?
The maths is exact for the formula shown on the page. Accuracy in the real world depends on your inputs and on assumptions the formula cannot see, so treat the output as a well-grounded estimate rather than a quote.
Can I use it on my phone?
Yes. The page is responsive, weighs a few kilobytes and works offline once loaded, so it behaves the same on a phone as on a desktop.
This page is a focused version of the Calorie Calculator, which handles every variation in one place.
What people search for
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About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 15, 2026 · Calculation runs client-side · No data collected · Report an error