How Many Calories Do I Need to Bulk? Worked Example
You typed in your weight, got a number like 3,100, and now you're wondering if you should trust it or just eat "more." Trust it as a starting point. The answer is your maintenance calories plus about 550 a day, which adds roughly 1 lb (0.5 kg) a week. Then the scale decides whether the number was right.
The calculation, step by step
Take a 24-year-old man, 154 lb (70 kg), 5'10" (178 cm), light activity, lifting three days a week. This is the same math Bulky's calculator runs.
- Resting burn (Mifflin-St Jeor). 10 × 70 + 6.25 × 178 − 5 × 24 + 5 = about 1,698 calories.
- Activity. Light activity multiplies that by 1.375: about 2,334.
- Training. Two to three lifting days add 2.5%, four or more add 5%. Here: about 2,392. That's his maintenance.
- Surplus. One pound is roughly 3,500 calories, so 1 lb a week is about 500 a day. Bulky uses 0.5 kg a week, which is about 550. Target: about 2,940 calories.
- Protein. 1.6 g per kg of body weight: about 112 g a day. Fat and carbs fill the rest.
That's the whole formula. No supplement, no secret multiplier.
The part most guides skip: step 2 can move your answer by 1,000
The same man, same body, but we change how he describes his week:
- Sedentary, no lifting: about 2,590
- Light activity, 3 training days (above): about 2,940
- Moderate activity, 4 training days: about 3,310
- Very active, 5 training days: about 3,620
That's a gap of more than 1,000 between the lowest and highest picks, and nothing about his body changed. Most of us pick the activity level we wish we had. If you sit at a desk and lift three times a week, "light" is honest. "Moderate" is for people on their feet most of the day.
So which number do you eat?
Pick the honest one and treat it as a hypothesis. A calculator can't know your job, your fidgeting or your real step count. The error is real but unknown for any one person, and the fix is the same as in how to tell if you're actually in a surplus: log two weeks and compare weekly average weight.
- Average weight up about 0.5 to 1 lb (0.25 to 0.5 kg) a week: the number is right. Keep it.
- Flat after two full weeks of hitting the target: add 200 to 300 a day.
- Up more than 1 lb a week for a month: you're gaining faster than needed. Cut about 200.
Should the surplus be smaller?
If you've lifted for years and you're already fairly lean-looking, a +550 surplus buys more fat than you want. Half of it, about +275 a day, gives roughly 0.25 kg (0.5 lb) a week. Our man would eat about 2,670 instead of 2,940. Slower, but the same direction. A beginner who is underweight can run the full number.
Either way, the scale says what the formula can't.
Do this today
Write down your real week. How many hours are you on your feet, how many days do you actually lift, and which activity level fits that, not your plans. Run the calculator with it, then eat that number for 14 days before you change anything.
Where a photo helps
The formula only works if your log is real. Most people who "ate the target and didn't gain" were eating a few hundred less, from oil, sauce or a skipped snack. Taking one photo per meal is faster than typing it all in, and any item can be corrected afterward. Treat the scan as a very good estimate, not a food scale, and check the label when you have one.
Keep reading
- Lost Weight While Bulking? Find Out Why in Two Steps Scale down on a bulk? Check the weekly average, then the log. A worked 160 lb (73 kg) example shows how a "surplus" week turns into a quiet deficit.
- Gaining Weight Too Fast on a Bulk? How to Read the Trend Up 6 lb in three weeks and not sure it's muscle? Learn which gains are water, when to cut calories, and the exact 250-calorie adjustment to make.
- Weight Not Going Up on a Bulk? Raise Calories This Way Scale flat for two weeks on a bulk? Check three things first, then add 250 calories a day. Worked numbers for a 150 lb (68 kg) lifter.