How Many Calories Should I Eat While Lifting? (Cut, Maintain, Build)
By Twaka team ·
Last reviewed
The short answer: start from your TDEE, the calories you burn in a day with training included. To maintain, eat about that. To lose fat, eat about 20% less. To build muscle, eat about 10% more, a small surplus. Treat the number as a starting point, then adjust from your weight trend and your lifts over two or three weeks.
Worked example in kg
Take a 30-year-old man, 80 kg, 178 cm, who trains 3 to 5 days a week (moderately active). Our free TDEE and calorie calculator starts with those numbers:
| Daily calories | |
|---|---|
| BMR (at rest) | 1,768 kcal |
| TDEE / maintenance | 2,740 kcal |
| Fat loss (20% below) | 2,190 kcal |
| Lean gain (10% above) | 3,010 kcal |
Targets are rounded to the nearest 10 kcal. Put in your own details to check your own numbers.
How the number is worked out
The calculator uses the Mifflin-St Jeor equation (Am J Clin Nutr, 1990) to estimate your basal metabolic rate (BMR), which is roughly what you'd burn lying still all day:
- Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
For the example: 10 × 80 + 6.25 × 178 − 5 × 30 + 5 = 1,768 kcal.
Then it multiplies BMR by an activity factor to get TDEE:
| Activity level | Multiplier |
|---|---|
| Sedentary, little or no exercise | 1.2 |
| Light, 1 to 3 days a week | 1.375 |
| Moderate, 3 to 5 days a week | 1.55 |
| Active, 6 to 7 days a week | 1.725 |
| Very active, hard daily exercise or a physical job | 1.9 |
1,768 × 1.55 = 2,740 kcal.
One important detail: the multiplier already includes your training. Pick the level that matches a typical week, not your best one.
Cut, maintain or build?
Maintain (100% of TDEE). Your weight should stay roughly steady. A good choice if you're happy with your weight and just want to get stronger.
Cut (20% below TDEE). A moderate deficit for losing fat. In the example, that's 2,190 kcal.
Lean gain (10% above TDEE). A small surplus for building muscle. In the example, that's 3,010 kcal.
The calculator uses percentages rather than a flat number, so a bigger, more active person gets a bigger gap in calories than a smaller, less active one.
How to adjust from there
The formula gives you a sensible starting point, but it can be off for any one person. Your own data is the better guide:
- Eat close to your target for two or three weeks.
- Weigh yourself under the same conditions each time.
- If the trend isn't going the way you want, adjust by a small amount.
Why your lifts matter as much as the scale
A calorie number on its own doesn't tell you whether the diet is working. The comparison that matters is your weight trend against your lifts:
- Cutting: if your weight is drifting down and your sets are holding or going up, the deficit is about right. If the lifts are falling apart, it may be too big.
- Lean gain: if the scale climbs quickly and your lifts don't, move back toward maintenance.
That needs a written record of what you actually lifted. In Twaka, you type a set the way you'd say it, like Bench press 3 sets of 10 at 60kg, and it keeps the sets, weights and progress for you.
Frequently asked questions
How many calories should I eat to lose fat?
Start around 20% below your maintenance calories, a moderate deficit. Keep it steady for two or three weeks, watch your weight trend, and adjust by a small amount if nothing is moving.
What are my maintenance calories?
Your maintenance calories are your TDEE. Eat around that amount and your weight should stay roughly steady.
How many calories should I eat to build muscle?
Start around 10% above maintenance, a small surplus, and pair it with training where your lifts go up over time.
Should I eat back the calories I burn from exercise?
Not if your activity level already includes your training. You'd be counting the same sessions twice. Only add calories for something well outside your normal week.
Why does the calculator ask for my sex?
Mifflin-St Jeor uses a different constant for men (+5) and women (−161). At the same weight, height and age, that's a 166 kcal difference in BMR.
Sources
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247.
Get your number, then track your lifts
Work out your targets on the free TDEE and calorie calculator, then keep an eye on your training alongside the scale. Twaka is a plain-English training tracker for iPhone, now on the App Store. Download Twaka on the App Store.
General information, not medical or dietary advice. If you have a medical condition, are pregnant, or have a history of disordered eating, talk to a doctor or accredited dietitian before changing how you eat.
