// Muscle-Building Calculators

Bulking Calorie Calculator

Enter your details and how long you've been training to get a surplus range and the weight change to check it against.

Your details

Your result

Bulking target
2,896–3,160kcal/day
Maintenance
2,633kcal/day
Surplus
263–527kcal/day
Surplus
10–20% over maintenance
Expected gain
0.19–0.38kg/week
Protein
120–165g/day
  • A surplus is set as a share of maintenance rather than a fixed number of calories, because 10% of a 2,000 kcal maintenance and 10% of a 3,500 kcal one are not the same amount of food.
  • Start near the bottom of the range and let the scale decide. If you are gaining faster than 0.38 kg a week averaged over three to four weeks, the surplus is larger than you need; slower than 0.19 kg and it is too small to support the training.
  • Some of the weight gained in a surplus is fat and some is fluid and gut content. No calorie target makes weight gain lean on its own — training, protein and the size of the surplus decide the ratio.
  • Newer trainees can use the wider end of the range because they add lean tissue fast enough to make use of it.

Estimates are for general guidance only and are not medical advice. For a personalised plan, book a free guided tour at RPM Gym.

What your result means

The target is a range, not a number, and the range is a percentage of your maintenance rather than a fixed amount of food. A 300 kcal surplus is a 15% intervention for someone maintaining on 2,000 and half that for someone on 4,000. Those aren't the same instruction.

Training experience sets how wide the range is. Novices and intermediates get 10-20% over maintenance; advanced lifters get 5-10%, because they add lean tissue slowly enough that the extra food mostly becomes fat. That's the single biggest error in most bulks — a beginner's surplus run by someone six years in.

The expected weekly gain is the part that matters most. The calorie figure is a starting estimate; the scale is the measurement. If you're gaining faster than the top of that range averaged over three or four weeks, the surplus is bigger than you need.

Some of what you gain will be fat, and some will be fluid and gut content from simply eating more. No calorie target changes that on its own. What shifts the ratio is the size of the surplus, whether the training is actually progressing, and whether protein is adequate.

How it is calculated

Shared gain model: a proportional surplus over estimated maintenance

Maintenance = Mifflin-St Jeor BMR × activity factor Surplus: novice and intermediate 10-20% · advanced 5-10% Target = maintenance × (1 + surplus) Expected weekly gain: 0.25-0.5% of bodyweight · advanced at the lower end

What it assumes

  • No single optimal surplus for muscle gain has been established, which is why this is a range expressed as a proportion rather than a fixed calorie figure.
  • Maintenance is an estimate carrying roughly ±10% error before you start. The weekly weight check exists to correct for that.
  • The weekly gain figures assume resistance training is happening and progressing. A surplus without progressive training is just a surplus.
  • Protein is set from the shared muscle-gain range, 1.6-2.2 g per kg of bodyweight.

Units and rounding

  • Weight in kilograms, height in centimetres, age in years.
  • Calories in kilocalories per day; expected gain in kilograms per week to two decimal places.
  • An unrecognised training experience defaults to the intermediate band, never the advanced one.

Worked example

A 72 kg man, 175 cm, 24, training four days a week, first year of serious lifting.

  1. Maintenance ≈ 2,633 kcal/day
  2. Novice surplus = 10-20% → 263-527 kcal
  3. Target = 2,896-3,160 kcal/day
  4. Expected gain = 72 × 0.25-0.5% = 0.18-0.36 kg/week

Start near 2,900 and watch the scale. Around 0.25 kg a week averaged over a month means it's working. Half a kilo a week means cut the surplus; nothing at all after three weeks means add roughly 200 kcal.

Limitations

  • Nobody gains only muscle. Even a well-run surplus adds some fat, and the honest ratio for a trained lifter is closer to even than the internet suggests.
  • Rate of muscle gain falls sharply with training age. A beginner may add a kilogram of lean mass in a good month; someone six years in may take a year for the same, and no calorie target changes that ceiling.
  • Maintenance moves as you gain. Recalculate every 4-5 kg or the surplus quietly shrinks to nothing.
  • The weekly gain figures are averages across weeks, not targets for any single week. Water, gut content and sodium swing daily weight by more than a week's real gain.
  • If weight is climbing well above the range and the lifts aren't moving, the extra food isn't going where you want it. That's a training problem, and eating more won't fix it.

What to do next

  • Start at the bottom of the range. It's much easier to add 200 kcal after three flat weeks than to unpick two months of unnecessary fat gain.
  • Weigh yourself under the same conditions three or four times a week and use the weekly average. Daily readings will tell you a story that isn't happening.
  • Check the lifts as well as the scale. Weight going up while working weights stay flat is the clearest sign the surplus is too large or the programme isn't progressing.
  • Plan the exit before you start. A gaining phase that runs until the mirror forces the issue always ends with a longer cut than the one you'd have chosen.

Sources

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// Frequently Asked

Questions, answered.

How many calories should I eat to bulk?

Roughly 10-20% above your maintenance level if you're in your first few years of training, 5-10% if you're advanced. For a maintenance of 2,600 that's about 2,900-3,100 or 2,700-2,900 respectively. Start at the bottom and let the scale decide.

How fast should I gain weight while bulking?

About 0.25-0.5% of bodyweight a week for most people, so 0.2-0.4 kg for someone at 80 kg. Advanced lifters should sit at the lower end. Faster than that and the additional weight is mostly fat.

What's the difference between a lean bulk and a normal bulk?

The size of the surplus, and that's all. A lean bulk sits at the bottom of the range and accepts slower gain for a better ratio; a larger surplus gains faster and carries more fat with it. This page gives you the range so the choice is yours rather than a label's.

Can I build muscle without gaining fat?

Some, sometimes. Beginners, people returning after a break and those with higher body fat can gain muscle while losing fat, usually at or near maintenance. For a trained lifter in a surplus, some fat gain is part of the deal.

How long should a bulk last?

Long enough to make the fat gain worth it, which for most people means three or four months minimum. Ending after six weeks means the ratio of fat to muscle is at its worst just as you stop.

How is this different from the calorie calculator?

That page gives you one target for whichever goal you pick. This one is built for a gaining phase specifically: it takes training experience, gives you a surplus range rather than a number, and pairs it with the weekly weight change you use to check the number was right.

A surplus without progressive training is just a surplus.

The food is the easy half. Getting the lifts to move so the extra calories have somewhere to go is what a free guided tour at RPM Gym in Al Manhal is for.

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