Calorie Counter by fatsecret built its following on food logging: scan a barcode, search a meal, and watch a running daily total. But most people who search “calorie calculator” are not ready to log anything yet. They just want one number: how many calories a day, given their body and how active they are. So we built Calorie Gauge, a free calculator that runs the standard Mifflin-St Jeor formula right here in your browser. Move a slider and your maintain, lose, and gain targets update instantly.
Work out your daily calories
It opens with a working example already filled in: 30 years old, 170 cm, 70 kg, moderately active. Drag the sliders or type your own numbers to make it yours.
How to use it
Set your sex, age, height, and weight with the sliders, or type exact numbers into the fields above them. Switch the toggle at the top between metric (cm, kg) and imperial (inches, pounds) at any time; your figures carry over automatically, they just get reread in the other unit. Pick an activity level from sedentary to very active, five buttons that map to the standard multipliers used in sports nutrition.
Three cards update the moment you touch a control: your maintenance calories, a lose-weight target 500 kcal below it, and a gain-weight target 500 kcal above it. The bar chart below plots all three against a dashed line marking your resting need (BMR), so you can see at a glance how much of your daily burn comes from just being alive versus moving around. There is no calculate button, because there is nothing to wait for. Your last inputs are saved on your device, so they are already there the next time you open the page. Nothing leaves your browser.
How it compares to Calorie Counter by fatsecret
Calorie Gauge does one job: turn your body stats and activity level into a maintain, lose, and gain calorie target, instantly, on anything with a browser. The full Calorie Counter app goes much further. It logs every meal against a barcode and food database of millions of items, tracks macros and micronutrients over weeks and months, syncs with fitness trackers, and adjusts your targets as your logged weight changes.
We kept the core loop: adjust your numbers, watch the targets and the chart move. We deliberately left out food logging, barcode scanning, and progress tracking, because a page you land on mid-search should answer the one question you came with in a few seconds, not ask you to create an account and start logging meals first.
Our honest advice: use Calorie Gauge when you want a quick starting number, or when you are explaining how TDEE and calorie deficits work to someone without either of you installing anything. Install the full app when you are ready to actually log what you eat and want your targets to adjust as your real weight changes over time.
Get the full app
Calorie Counter by fatsecret is free on Android, with food and recipe logging, a barcode scanner, and a large nutrition database built around it.
Frequently asked questions
How do I calculate my daily calorie needs?
Start with your BMR (the calories your body burns at rest), using the Mifflin-St Jeor formula: 10 x weight in kg + 6.25 x height in cm - 5 x age, plus 5 for men or minus 161 for women. Multiply that by an activity factor from 1.2 (sedentary) to 1.9 (very active) to get your total daily energy expenditure, or TDEE. The calculator above runs this live as you move the sliders, in either metric or imperial units.
How many calories should I eat to lose weight?
A common, sustainable approach is a deficit of about 500 kcal a day below your maintenance level, which works out to roughly a pound (0.45 kg) a week, since a pound of body fat holds about 3,500 kcal. Very large deficits are harder to sustain and can cost lean muscle along with fat, so the calculator uses 500 kcal as its default lose-weight target rather than a more aggressive number.
Is this the same as tracking calories in Calorie Counter by fatsecret?
No. Calorie Gauge only calculates a target number; it does not log what you actually eat. Calorie Counter by fatsecret is a full food diary with a barcode scanner and nutrition database for tracking real intake against that target day by day. Use the calculator to find your number, then use a logging app if you want to track against it.
Does it work offline and is it free?
Yes to both. It is completely free with no signup, and once the page has loaded it keeps working without a connection. Your last inputs are saved in your browser’s local storage on your device only.
Is this calculator accurate, and is it medical advice?
The Mifflin-St Jeor formula is one of the more accurate calorie-estimation equations available and is widely used in sports nutrition, but it is still an estimate. Individual metabolism varies, and this tool is not a substitute for medical advice. Talk to a doctor or registered dietitian before starting a weight-loss or weight-gain plan, especially if you have a health condition.
Is this the official fatsecret app?
No. Calorie Gauge is an original tool we built, inspired by the calorie-math problem that Calorie Counter by fatsecret solves. It is not affiliated with, endorsed by, or connected to FatSecret. If you want food logging, a barcode scanner, and nutrition tracking over time, get the official app from the store links above.
