Maintenance calories for a 45 kg man

A 30-year-old man weighing 45 kg at 178 cm burns about 2,125 calories a day lifting four days a week with 7,500 to 10,000 daily steps, and about 1,700 with a desk job and little activity. To lose about 0.23 kg a week, eat around 1,880 a day.

Updated

About you

Body fat is optional.

Sex
years
kg
cm
Training sessions a week

Your phone's weekly average is the honest number. Steps move your TDEE more than gym days do.

%

Adds Katch-McArdle and Cunningham, which work from lean mass instead of total weight.

Your TDEE

2,125kcal/day
BMR at rest (Mifflin-St Jeor)
1,420 kcal
Activity factor
×1.50

Calorie targets

Macros for cut

Protein
99 g
Carbs
253 g
Fat
52 g

Your BMR by formula

Without a body fat %, only Mifflin-St Jeor can run. With one, the lean mass formulas join in and Katch-McArdle sets your TDEE.

Mifflin-St Jeor1,420 kcal
Katch-McArdleNeeds body fat %
CunninghamNeeds body fat %

Your TDEE at each activity level

The classic multipliers most calculators use, applied to your BMR. Use it to sanity check the steps and sessions estimate above.

Activity levelMultiplierTDEE
SedentaryDesk job, little exercise×1.21,700 kcal
Lightly activeExercise 1 to 3 days a week×1.3751,950 kcal
Moderately activeExercise 3 to 5 days a week×1.552,195 kcal
Very activeHard exercise 6 to 7 days a week×1.7252,445 kcal
Extremely activePhysical job plus hard training×1.92,695 kcal

The calculator above starts at 45 kg. Change your age, height, steps and training days for your own number.

TDEE by height and activity at 45 kg

Worked out with Mifflin-St Jeor for a 30-year-old man. Find your height, then read across to how active you are.

TDEE by height and activity at 45 kg
HeightSedentaryLightly activeModerately activeVery activeExtremely active
160 cm1,5651,7952,0252,2502,480
165 cm1,6051,8352,0702,3052,540
170 cm1,6401,8802,1202,3602,600
175 cm1,6801,9252,1702,4152,660
180 cm1,7151,9652,2152,4652,715
185 cm1,7552,0102,2652,5202,775
190 cm1,7902,0502,3152,5752,835
195 cm1,8302,0952,3602,6302,895

Calories to cut, maintain or bulk at 45 kg

Targets for a 30-year-old man at 178 cm who lifts four days a week and walks 7,500 to 10,000 steps a day, with the pace set as a share of bodyweight.

Calories to cut, maintain or bulk at 45 kg
GoalCalories a dayWeekly change
Fast cut1,755−0.34 kg
Cut1,880−0.23 kg
Slow cut2,005−0.11 kg
Maintain2,125None
Lean bulk2,250+0.11 kg

TDEE by age at 45 kg

The formula takes 5 calories a day off resting energy for every year of age, so the same body burns a little less each decade. Worked out at 178 cm.

TDEE by age at 45 kg
AgeBMRSedentaryModerately active
20 years1,4701,7602,275
30 years1,4201,7002,195
40 years1,3701,6402,120
50 years1,3201,5802,040
60 years1,2701,5201,965

How much protein at 45 kg

Most of the research on lifters lands between 1.6 and 2.2 g of protein per kilogram of bodyweight a day. At 45 kg that is 72 to 99 g a day, with the top of the range most useful during a cut.

Other bodyweights

TDEE Calculator

Frequently asked questions

How many calories should a 45 kg man eat to lose weight?

Start from maintenance and take off enough to lose about 0.5% of bodyweight a week. For a 30-year-old man at 178 cm who lifts four days a week, maintenance is about 2,125 calories, so a cut sits near 1,880 a day. Weigh in daily, compare weekly averages, and adjust by 100 to 150 calories if the trend is off after two to three weeks.

How many calories should a 45 kg man eat to build muscle?

A lean bulk gains about 0.25% of bodyweight a week, which at 45 kg is a surplus of about 125 calories a day. That puts a man at 178 cm who lifts four days a week near 2,250 calories a day, with 72 to 99 g of protein.

How many calories does a 45 kg man burn at rest?

At rest, a 30-year-old man at 178 cm and 45 kg burns about 1,420 calories a day: that is the BMR. With a desk job and little exercise, the total for the day is about 1,700 calories.