Tutorials

Calorie Calculator: a quick guide

Estimate daily calorie needs based on age, sex, activity level and goal.

Knowing roughly how many calories you need is the foundation of any nutrition plan. The ChrysoKit Calorie Calculator uses well-established formulas to estimate your maintenance calories, then adjusts for your goal.

Why use it

Most calculators stop at maintenance. We add a target adjustment (gain, lose, maintain) so you walk away with a number you can actually use.

How to use the Calorie Calculator

  1. Enter your age, sex, height and weight.
  2. Pick an activity level from the descriptions.
  3. Pick a goal: maintain, lose or gain.
  4. Read the suggested daily intake.

Features worth knowing

Mifflin-St Jeor formula

The most accurate of the common BMR formulas.

Activity multipliers

Sedentary to very active, with concrete examples.

Goal adjustment

Adds or subtracts a sensible deficit or surplus.

Pro tips

  • Calorie targets are estimates. Adjust based on what the scale and the mirror tell you over a few weeks.
  • Activity level is the easiest input to overestimate. Most desk workers are 'sedentary' even if they exercise a few times a week.
  • Slow changes (250-500 kcal deficit or surplus) are more sustainable than aggressive ones.

Privacy first. The Calorie Calculator runs entirely in your browser. Nothing you enter is sent to a server.

Treat the Calorie Calculator as a starting line. Track for a couple of weeks, then adjust based on results.

Open the tool: Calorie Calculator →

Why the scale stalled: a deficit troubleshooting guide

The calculator said 2,100 kcal for a steady half-kilo per week; six weeks in, the scale has stopped. Before concluding the math is broken, walk the checklist that coaches actually use.

First: tracking drift. Logging accuracy decays predictably... oils, sauces, weekend meals and bites-while-cooking quietly exit the ledger. Studies of self-reported intake find underestimation of 20-40% is normal, not exceptional. A one-week return to weighing and logging everything usually locates 300 missing calories without drama.

Second: the moving target. A body 5 kg lighter burns roughly 100-150 fewer calories daily at rest and during movement. The original TDEE estimate has expired; recalculate at the new weight and the "stall" often turns out to be arithmetic.

Third: invisible adaptation. Beyond the formula's reach, bodies in deficit reduce spontaneous movement... fidgeting, pacing, taking stairs... by hundreds of calories daily without consulting you. A step counter makes this visible; a daily step floor counters it.

Fourth: water masking. Fat loss continues during scale stalls surprisingly often, hidden under water retention from stress, sodium or new training. Weekly averages and a tape measure tell the truth daily weigh-ins obscure.

Only after these four does "eat less" enter the conversation... and usually it never needs to. The number was a hypothesis; this is the experiment.

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ChrysoKit Team

The team behind ChrysoKit. We build small, useful, fast, free tools for people who would rather get on with their day than fight a website.