Bulking Calorie Calculator

How many calories to bulk. Actually.

Your maintenance, your surplus, and the daily target to gain weight. Built on your lean mass, not your height.

Units
You are

Sex and age don't touch the metabolism math here. They only set the ceiling on how fast you can realistically add muscle.

lb
years
Body fat (best guess)

Pick the band that looks closest. Adjacent bands move the result by roughly 60–90 calories, so a rough estimate is enough.

Daily movement, outside the gym
Training sessions per week
Lifting experience
What you're gaining for
Have you ever weighed more than you do now?
Over the last few weeks, your weight has been
How fast you want to gain

These options are already capped at what your training age, sex and age can realistically turn into muscle. Eating past the ceiling adds fat, not size.

Why this calculator asks more than the others

The short answer

Almost every bulking calculator online runs the same equation on height, weight, age and sex. This one runs on your lean body mass, which is the tissue actually burning the calories.

Most calorie apps are built for weight loss. The gain setting is the same math pointed the other way: same assumptions, same blind spots, all of it designed for someone trying to eat less. If you've spent six months failing to gain inside one of them, that's the reason.

The standard tool is the Mifflin-St Jeor equation. Four inputs, one activity multiplier, done. It's fine, and it's everywhere, but it's estimating your lean mass from your height because it has nothing better to work with. Two men at 5'10" and 175 lb get the same number whether one is a lifter at 12% body fat and the other has never trained.

Ask about body fat instead and the guesswork disappears. That's the Katch-McArdle equation, and it's what this calculator uses. Which is why there's no height field on this page. It doesn't need one.

Movement and training are counted separately

Most calculators collapse your entire life into a single "activity level" dropdown, which forces a desk worker who lifts four times a week and a warehouse worker who never trains into the same bucket. Here they're two questions, because they're two different things. Steps scale your resting burn. Training adds calories on top, sized to your bodyweight and how hard you can actually push a session.

Your surplus gets adjusted, not just added

The surplus starts from the rate you picked, at roughly 7,700 calories per kilogram gained. Then it moves: leaner bodies handle a bigger surplus before it turns to fat, and someone who's been slowly losing weight needs more of a push to flip the trend than someone already creeping upward. If you've been heavier before, your body has some memory of it, and the number reflects that too.

There's a ceiling on muscle, and it's lower than most people think

Your body can only build so much muscle in a month, no matter how much you eat:

Women build at roughly half these rates, and the ceiling drops about 1% a year after 30. That's why the rate options above stop where they do. Eating for a rate your body can't use doesn't add muscle. It adds fat.

What to do with the number

Eat it, consistently, for two to three weeks. Then look at what the scale did, not what it did on any single day.

That loop is the whole game, and it's also where nearly everyone falls off. Doing it by hand means weighing daily, averaging honestly, remembering what you ate three weeks ago, and adjusting without overreacting to a bad Monday.

This number is a starting guess

Worth being blunt about: every calorie calculator, including this one, is a population average wearing your inputs. It has never seen your metabolism. Two people with identical entries on this page can differ by several hundred calories a day in real life, and no formula can tell you which one you are.

What settles it is data. Once there are a few weeks of intake and weigh-ins to compare, your real maintenance stops being a guess and becomes something you can measure. That's what BulkMode is doing in the background:

That's the learning. Separately from it, the app eases you in: your first week sits below the full target and steps up over five weeks, which is the "Ease into it" switch above. That part isn't the app reacting to you, it's a deliberate on-ramp, because a bulk you quit on day three isn't a bulk. For the reasoning behind the numbers, read how many calories to bulk; for choosing the rate you plugged in above, clean bulk vs. dirty bulk; for the whole method, how to bulk the right way.

The part after the calculator.

You now have a number. The hard part is the eight weeks that follow it.

  • Snap your food. Calories and macros, instantly. No searching, no typing.
  • A target that moves with you. It starts where this page did, then learns your real maintenance from your weigh-ins.
  • See the trend, not the noise. The scale wobbles day to day. Your real progress doesn't.
  • No guilt for eating. No red warnings, no shame. Hitting your calories is a win, not a problem.
BulkMode metabolism screen showing a calorie target adjusted from real weigh-in data

Stop guessing at the number.

Free to start. Built only for gaining.

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Calculator FAQ

Your maintenance calories plus a surplus sized to the rate you want to gain. A quarter to half a pound per week is the range most people should sit in, which works out to roughly 300–500 calories per day above maintenance. The calculator on this page works out both numbers for you: what you burn, and what to eat on top of it.
Because it doesn't need it. Height is only in the standard Mifflin-St Jeor equation as a stand-in for how much lean tissue you're carrying. If you estimate your body fat instead, you get at lean mass directly and the proxy becomes redundant. This calculator uses the Katch-McArdle equation, which runs on lean body mass, so height never enters the math.
When your body fat estimate is reasonable, yes. Lean tissue is what burns calories at rest, so a formula that measures it directly beats one that infers it from height and age. When your body fat estimate is badly off, Katch-McArdle inherits that error. Either way both are estimates, and the only thing that settles it is what your weight actually does over a few weeks of consistent eating.
Pick the range that looks closest. The calculator uses broad bands, not exact percentages, so being a few points off moves the result by a small amount rather than breaking it. Most people who lift can place themselves within one band by eye, and the practical difference between two adjacent bands is around 60–90 calories a day.
Roughly a quarter to half a pound per week for most people. Your body can only build so much muscle per month, and that ceiling depends on how long you've trained, your age, and your sex. Eating past it doesn't build more muscle, it just adds fat you'll have to diet off later. The rate options in this calculator are already limited to what your profile can realistically use.
That's deliberate. Jumping straight to a full bulking target is the fastest way to spend three days too full to eat and then quit. BulkMode starts you below the number and steps you up to it over your first five weeks, so the habit sticks before the volume does. Turn on "Ease into it" above to see exactly what your first week looks like.