How Many Calories Should You Eat to Lose Weight?

It’s the most-Googled question in weight loss: how many calories should I eat to lose weight? The honest answer is “it depends” — but that’s useless, so let’s turn it into an actual number you can use today.

Start with your TDEE

Everything begins with your TDEE — Total Daily Energy Expenditure, the calories you burn in a day. To lose weight, you eat below it. To find yours, use a step-based TDEE calculator rather than guessing a vague “activity level,” because that guess is where most people’s numbers go wrong.

Once you have your TDEE, the rest is simple arithmetic.

How big should the deficit be?

A pound of fat stores roughly 3,500 calories, and a kilo about 7,700. So a daily deficit adds up like this:

• 300–500 cal/day deficit → ~0.25–0.5 kg (0.5–1 lb) per week
• 500–750 cal/day deficit → ~0.5–0.75 kg per week

A good default for most people is a moderate 15–20% deficit below TDEE. If your TDEE is 2,400, that’s a target of roughly 1,900–2,050 calories.

Why bigger isn’t better

It’s tempting to slash calories hard and lose faster. Resist it. Aggressive deficits come with real downsides:

• More muscle loss (you want to lose fat, not muscle).
• Worse energy, sleep and mood — which tanks adherence.
• Stronger hunger, which is the number-one reason diets get abandoned.

The best deficit isn’t the biggest one — it’s the biggest one you can actually sustain for months. A 400-calorie deficit you keep beats an 800-calorie one you quit in two weeks.

Don’t go below your floor

As a general safety floor, most guidance suggests not dropping below ~1,200 calories/day for women and ~1,500 for men without medical supervision. Below that it’s hard to hit your protein and micronutrient needs, and adherence usually collapses anyway.

The mistake that stalls everyone

Here’s what actually trips people up: your calorie target isn’t a “set it once” number. As you lose weight, your TDEE drops (a smaller body burns less), and your daily activity naturally fluctuates. The target that worked in month one is often too high by month three.

That’s why guessing once and never revisiting it leads to the dreaded plateau. The fix is to track your intake and your weight trend over time, and adjust when the trend flattens — not to crash harder. (More on the maddening day-to-day scale noise here.)

Make it concrete

1. Find your TDEE from your real daily steps.
2. Subtract 15–20% to set your starting target.
3. Log your intake and watch the weekly trend.
4. If the trend stalls for 2–3 weeks, trim another ~100–150 calories or add some steps.

That’s the whole system — and it’s exactly what trimtrack automates for you. It turns your steps into a personalised target and tracks the trend so you know when to adjust, instead of guessing. It’s more than a calorie calculator.

Want your number? Start with trimtrack and get a calorie target built on how you actually move.