How many calories should you actually eat?

Calorie Calculator

Ever wondered whether your rest and workout day targets should be different? They 100% should. And they should be dialed to HOW HARD you really train.

Here's what this calorie calculator does for you: it tells you how many calories to eat on rest days vs workout days by reading your personal data (age, weight, activity, and your goal). Then it finds your maintenance, splits it, and gives you a reliable number to follow.

We want to make it as USEFUL as possible for most people, so we give you a range for both days you can actually use.

Your details

Sex
yr
Height
ft
in
lb
Goal
Training days per week

How many days you actually lift or train. This sets the gap between your rest and workout targets.

Your two targets

Rest day

2,980

2,850–3,100 cal

Workout day

3,200

3,050–3,350 cal

These are estimates. Your real numbers move with how hard you train and what you burn. APEX tracks both and corrects the target for you. Download APEX free

BMR

1,989

Maintenance

3,100

Goal target

2,950–3,250

Deficit

±0

Activity factor

×1.55

Equation used

Ten Haaf

Macros

Rest: P 145 · C 375 · F 100 g

Workout: P 145 · C 475 · F 80 g

Where your maintenance comes from

Resting (BMR) 1,989Active 1,111

Rest day vs workout day

Rest day2,980 cal
Workout day3,200 cal
How we calculated this

Equation: Ten Haaf, because you train 3+ days a week.

Activity factor: ×1.55 on your BMR of 1,989.

Maintenance (TDEE): 3,100 calories.

Goal: ±0 versus maintenance.

How many calories do you actually need?

It really depends on your goals. First, understand that your body burns calories three ways:

1. Resting energy

What keeps your heart beating and your body warm, even asleep. That's your BMR, 60 to 75% of your day.

2. TDEE (total daily energy expenditure)

Everything you do day to day: walking, cooking, standing, training. Add that to your resting energy and you get your TDEE.

3. Added up

Add your resting and active energy together and you get your maintenance calories, the total that holds your weight. We split it by rest day and training day. For most people the difference is 200 to 400 calories, though it varies a lot from person to person.

Now, the amount you need depends on your goal: a DEFICIT (eat under maintenance to lose weight and fat), a BULK (eat over maintenance to add weight and muscle), or MAINTENANCE (eat what you burn to hold your weight, or recomp).

How this calculator works

Most calculators still run the Harris-Benedict equation from 1919. It overestimates. Better math has existed for decades.

We use what the research backs. The default is Mifflin-St Jeor, the most reliable for most people. Enter your body fat and we switch to Cunningham, built on lean mass. Train 3 or more days a week and we run Ten Haaf, sharper for trained bodies.

It adapts your inputs to the right equation automatically, so you get the most accurate, useful number for your goals.

Rest days vs workout days

Most people burn a lot more on a training day than a rest day.

So why eat the same?

On training days you need a few extra calories to fuel the work, usually as carbs to top up your energy stores.

On rest days, to stop you overshooting on low-activity days, the calculator drops to a lower range. It holds your goal without overcomplicating things.

Adjusting for your goal

Your goal shifts the target up or down from maintenance.

To lose fat, eat 300 to 600 below maintenance. That drops fat at a pace you can hold. The exact number shifts with your age, weight, and real activity.

To build muscle, eat 200 to 500 above maintenance, no more. Aim to gain 0.25 to 0.5% of your bodyweight a week. Go higher and you build more fat than muscle, and you'll cut it off later.

To maintain or recomp (lose fat and build muscle at once), stay within 100 to 200 calories of maintenance. Beginners do better with a small deficit, since they build muscle fast anyway. Experienced lifters do better with a small surplus, the most reliable way to gain without wasting time.

Why the number is an estimate (and what to do about it)

No calculator can hand you a perfect number. Any that claims to is lying.

Even Mifflin-St Jeor, the most reliable equation there is, misses by more than 10% for about a third of people. For total daily burn it's worse: the best-validated equations get within 10% for fewer than half.

Most of your burn is invisible to any equation. Everyday movement alone can differ by 2,000 calories a day between two people the same size. Wearables misread calories by over 25%, and food logs under-report by 12 to 50%.

So the number here is an ESTIMATE, as close to the truth as the math gets.

That's why APEX exists. What you burn shifts with your workouts, your steps, and how your body responds to the diet over weeks.

A calculator that never corrects is a dead end. APEX fixes that, and this page is a sneak peek of what it does once you sign up.

Macros, briefly

Calories decide your weight. Macros decide whether the weight you keep is muscle.

Here's how we set each one:

Protein: start at 1.6 g/kg or 0.7 g/lb, then push it toward 2.2 g/kg or 1.0 g/lb when you cut. Hit it every day.

Fat: set a floor at 0.7 to 1.0 g/kg or 0.3 to 0.5 g/lb. It runs your hormones, so don't drop below it.

Carbs: fill whatever calories are left, and put more of them on training days.

That's enough to start. The calculator gives exact grams for your rest and workout days.

Common questions

How many calories should I eat a day?

Match your maintenance, then adjust for your goal. Most adults sit between 1,800 and 3,000 a day. To lose fat, drop 300 to 600. To build muscle, add 200 to 500. The calculator gives your exact rest day and workout day targets.

What's the difference between BMR, TDEE, and maintenance calories?

BMR is what you burn at complete rest. TDEE is BMR plus everything you do in a day, also called your maintenance calories: the total that holds your weight steady. Eat under it to lose, over it to gain.

What's the difference between resting and active calories?

Resting calories keep you alive, 60 to 75% of your daily burn. Active calories come from moving: walking, daily activity, and workouts. Together they make your maintenance. Training pushes active calories up, so your workout day target is higher.

How many calories to lose fat or build muscle?

To lose fat, eat 300 to 600 below maintenance and lose 0.5 to 1 kg (1 to 2 lb) a week. To build muscle, eat 200 to 500 above and gain 0.25 to 0.5% of bodyweight a week. Go faster and you add fat or lose muscle.

Should I eat more on training days?

Yes. You burn more on training days, and your muscles want carbs to recover. Eat more on workout days and less on rest days, balanced to the same weekly average, and you fuel training without touching your goal. Protein stays steady. Carbs move.

Are calorie calculators accurate?

They give you a solid starting estimate. An exact daily number, no calculator can manage. The strongest equation misses by 10% or more for a third of people, and movement, watch errors, and food logging widen the gap. Your real target comes from tracking your weight trend, which is what APEX does.

How few calories is too few?

Below roughly 1,500 for men and 1,200 for women, you start losing muscle, energy, and hormones along with fat. The calculator won't show a target under these floors without a warning. If you need to go that low, add movement before cutting food further.

Which equation do you use, and does metric or imperial matter?

We use Mifflin-St Jeor by default, Cunningham if you enter body fat, and Ten Haaf if you train 3+ days a week. We pick it automatically. Metric or imperial makes no difference: we convert to metric, run the math, and convert back.

Turn your estimate into your real number.

You've got your best estimate. Now let it improve every week. APEX tracks your training, steps, and weight trend, then adjusts your two targets to match what your body is doing. That's the number no calculator can reach alone.

Download APEX free

This is general information, not medical advice. Pregnant, managing a health condition, or with a history of disordered eating? Talk to a professional first. Read our full disclaimer.