Frequently asked questions
Everything you might want to know about tracking calories and macros with Fettle.
Is Fettle free?
Yes. Fettle is completely free. There is no paid tier for the core tracker, no ads, and no account required. You can track calories, macros, scan barcodes and log your weight without paying anything.
Does Fettle work with UK supermarket foods?
Yes. Fettle is built for the UK. It searches Open Food Facts, which covers branded and own-brand products from Tesco, Sainsbury's, Asda, Aldi, Lidl, M&S, Morrisons and Waitrose, plus a built-in set of common UK foods for instant, offline search.
How does barcode scanning work?
Point your phone camera at a product barcode and Fettle looks it up in the Open Food Facts database, then fills in the calories and macros for you. It reads standard retail barcodes such as EAN-13. Scanning needs camera permission and a secure (https) connection, which any phone browser provides.
Do I need to create an account?
No. Fettle has no sign-up. Your diary, goals and weight are saved on your own device in your browser. You can export a backup file at any time and import it on another device.
How does Fettle work out my calorie target?
Fettle estimates your maintenance calories using the Mifflin-St Jeor equation (from your sex, age, height, weight and activity level), then adjusts for your goal. Losing or gaining a set amount per week changes the target by roughly 7,700 calories per kilogram, spread across the week. You can also set a custom target.
What macros does Fettle track?
Fettle tracks the three main macronutrients: protein, carbohydrate and fat, in grams, against a daily target. Your macro target comes from your calorie goal and a split you choose (balanced, high-protein, low-carb or keto), using 4 calories per gram of protein and carbohydrate and 9 per gram of fat.
Is Fettle a good free alternative to MyFitnessPal?
Fettle is a free, UK-focused alternative for people who mainly want to count calories and macros and scan barcodes without a paywall. It keeps the core tracking free and works well with UK foods. It does not (yet) have every feature of larger paid apps, such as recipe importing or multi-device cloud sync.
Are the calorie and macro figures accurate?
The built-in foods use standard UK reference values and branded items come from Open Food Facts, a crowd-sourced database. Treat totals as a good working estimate rather than clinical data. You can edit any amount or create a custom food from a product's label.
Can I use Fettle on my phone like an app?
Yes. Open Fettle in your phone browser, then choose "Add to Home Screen". It installs as a web app with its own icon and runs full-screen, and your food diary works offline.