# Calorie and macro calculator

By Ryan Bulcher, CalTrak developer. Updated November 3, 2026.

Source: https://caltrak.app/calorie-calculator

Get your daily calorie target and macros in a few seconds. This is the same math CalTrak's goal wizard uses. It runs in your browser and nothing you type gets sent anywhere.

## How the calculator works

1. **Resting burn (BMR).** The Mifflin-St Jeor equation estimates what your body burns at rest: 10 × weight in kg, plus 6.25 × height in cm, minus 5 × age, then plus 5 for men or minus 161 for women.
2. **Maintenance (TDEE).** BMR times an activity factor, from 1.2 if you're sedentary up to 1.9 if you're very active. That's roughly what you burn in a day.
3. **Your goal.** A pound of body weight is about 3,500 calories, so losing 1 lb a week means eating about 500 calories a day under maintenance.
4. **A floor.** The target never drops below 1,200 calories a day for women or 1,500 for men. If your pace would need less, you get the pace that minimum supports instead.
5. **Macros.** Protein is based on your weight and activity, and goes up when you're losing weight to help keep muscle. When losing, carbs follow your activity level and fat fills the rest, kept between 20% and 40% of calories. Otherwise fat is about 30% and carbs fill the rest.

## How accurate is it?

Mifflin-St Jeor is one of the more accurate formulas for adults, but it's still a formula. Your real maintenance could be off by a couple hundred calories either way. The way to dial it in is to eat at the target for two or three weeks, watch your weight trend, and move it 100 to 200 calories if things aren't going the way you expected. [This guide walks through it](https://caltrak.app/guides/how-many-calories-to-lose-weight).

**Not medical advice.** This is for healthy adults. If you're pregnant or breastfeeding, under 18, have a medical condition or have a history of disordered eating, get a number from a doctor or registered dietitian.

## Track it in CalTrak

CalTrak's goal wizard runs this exact calculation, sets your targets in the app and tracks every meal against them. If you connect Apple Health or Health Connect, it can also add extra activity to your budget on days you move more.

## Questions people ask

**What is TDEE?**

TDEE stands for total daily energy expenditure. It's an estimate of how many calories you burn in a day, activity included. Eat about that much and your weight stays the same.

**What is BMR?**

BMR stands for basal metabolic rate. It's an estimate of what your body burns at rest just keeping you alive: breathing, circulation, your organs doing their thing.

**How many calories should I cut to lose a pound a week?**

About 500 a day under your maintenance, since a pound is roughly 3,500 calories. Everyone's a bit different, so adjust after a few weeks based on your weight trend.

**Is what I type saved or sent anywhere?**

No. The calculator runs entirely in your browser. Nothing is sent or stored.

## Get CalTrak

CalTrak is free on iPhone and Android. No account, no ads, no subscription, and AI logging is free. Your food log stays on your phone.

4.9-star App Store rating from 99 ratings; 4,000+ downloads across the App Store and Google Play.

- App Store: https://apps.apple.com/app/id6764352979
- Google Play: https://play.google.com/store/apps/details?id=com.ryanbulcher.caltrak
- Support: support@caltrak.app