Calorie Counter Apps in the UK: What to Look For

If you search for the best free calorie counter app in the UK, you get ranked lists of names. No ranking tells you whether an app understands that a UK packet of crisps is what Americans call potato chips. Three things decide that: what the app knows about UK food, which units it shows, and what it asks you to pay. I run all three on a new app before I read a single review. It takes ten minutes.

What should a calorie counter app know about UK food?

Before names, look at where an entry comes from. The UK’s own reference table is CoFID, the Composition of Foods Integrated Dataset, and the latest edition on the government page is the 2021 update. An app doesn’t have to use it, but it should tell you which database an entry came from.

Packaged food is more predictable, because the law behind UK labels says the energy value and the nutrients are given per 100 g or per 100 ml. So a good scan returns a per 100 g number and lets you type your own grams. Rolled oats have 379 kcal per 100 g in the USDA record, so a 40 g bowl is 0.4 × 379, which is 152 kcal.

Names are the harder part. A database built in the US may list the thing you eat under its American name, or not at all. Search these nine words in any app you try:

UK word	Word a US-built database may use
crisps	potato chips
biscuit	cookie
chips	fries
aubergine	eggplant
courgette	zucchini
rocket	arugula
mince	ground beef
swede	rutabaga
jacket potato	baked potato

If the app finds the UK word, good. If it only answers to the US word, you’ll translate every shop in your head, and that gets old by day three.

Branded entries need a second look. The same pack of biscuits may be listed several times with different numbers, so open the entry and look for a serving weight and a named source.

Run it on the five foods you ate most last week. The checks that hold in any country are in how to choose a calorie counter app, and I’d read that after this one.

What goes wrong when I log home-cooked food?

The state of the food, more than its name. I use a jacket potato as the example because everyone in the UK has eaten one and almost nobody weighs it. The USDA record for a raw potato with skin gives 77 kcal per 100 g. The record for a baked russet, flesh and skin gives 95 kcal per 100 g, because baking drives out water. It lists a large baked potato at 299 g, so that potato comes to 0.95 × 299, which is 284 kcal.

Now weigh the same potato after baking and pick the raw entry. The app multiplies 77 kcal by 2.99 and shows 230 kcal. That’s 54 kcal short, a 19% undercount, from one choice in a drop-down. Easy to miss.

Toppings travel on separate lines. Cheddar is 408 kcal per 100 g in the USDA record, so 30 g grated on top adds 122 kcal. The potato with its cheese comes to 406 kcal. Beans, butter and coleslaw each get a line and their own grams.

Search “jacket potato” in the app you’re testing. A good one offers a baked entry and a raw one and says which is which. A weak one hands you a single number with no state. Match the entry to what the scale saw. Baked weight goes with the baked entry, and raw weight, taken before cooking, goes with the raw one.

Does the app show kcal, pounds and stone?

It should show what you already use. UK sources talk in calories, and the NHS gives average daily needs as around 2,000 calories for women and 2,500 for men. Those are averages, so your own goal will differ, and the app should let you edit it. If you read labels in kilojoules instead, the calorie counting app Australia post covers that side.

Weight is where the UK differs most. Scales and conversations run in stone and pounds, and a stone is 14 lb, or 6.35 kg. I worked out three common weights so you can check an app’s converter:

Weight in stone	Pounds	Kilograms
10 st	140 lb	63.5 kg
12 st	168 lb	76.2 kg
14 st	196 lb	88.9 kg

Type one in and watch what comes back. An app that only takes kilograms makes you do the sum before you’ve logged anything.

What do the 2,000 kcal and the per portion column on a UK label mean?

They give a pack some context, and neither is a goal for you. UK law sets the reference intakes for adults at 8,400 kJ or 2,000 kcal of energy. The same list gives 70 g of fat, 20 g of saturates, 260 g of carbohydrate, 90 g of sugars, 50 g of protein and 6 g of salt. A percentage on the pack is a share of those values.

The portion column is the part that trips up an app. A label may give figures per portion as well as per 100 g. It has to state the portion size and how many portions the pack holds, and the portion is whatever the maker prints. Take the 40 g bowl of oats from earlier: 152 kcal is 7.6% of 2,000 kcal. Now picture a pack that calls 30 g a portion, with 60 g in your bowl. The portion column is wrong for you. The per 100 g line is still right.

Scan a pack and try to replace the portion with your own grams. An app that keeps the maker’s portion and gives you no way to change it will be wrong at most of your meals. Keep the 2,000 kcal out of your goal field as well. Your goal comes from your size, age and activity, and the NHS averages above are only a starting point.

Why does the app’s kcal differ from the number on the pack?

Energy on a label is calculated. An app’s entry may come from a different calculation or an older recipe. UK labels give energy as kJ and kcal, worked out from the grams of each nutrient with the Annex XIV factors. Those are 4 kcal per gram of carbohydrate and of protein, 9 for fat, 7 for alcohol and 2 for fiber.

I ran the oats through them. The USDA record lists 13.5 g of protein, 5.89 g of fat and 68.66 g of carbohydrate per 100 g. The sum is 4 × 13.5 + 9 × 5.89 + 4 × 68.66, which is 381.6 kcal. The record itself says 379 kcal, because FoodData Central uses an Atwater specific factor for this food. The gap is 3 kcal, or 0.7%, and on a 40 g bowl it comes to about 1 kcal. Neither figure is wrong.

Bigger gaps can come from reformulation. foodDB, a research database fed weekly from six major UK supermarket websites, held 128,283 distinct products by June 2018. Among 903 pizzas it followed for six months, 10.8% changed their nutritional formulation.

Small gaps are normal. Within a few kcal per 100 g, I keep the entry. Further out, I copy the pack’s per 100 g figure into a food of my own and log from that.

Can an app tell me what is in a restaurant or takeaway meal?

Only where the restaurant publishes it. In England, businesses with 250 or more employees have had to show the energy content of food in kcal since 6 April 2022. They give the portion size too, with a line saying adults need around 2000 kcal a day. The guidance covers England only.

So large chains give an app something solid to copy, and your local café doesn’t. A corner-shop sandwich entry is an estimate, however tidy it looks. Menus change. If a chain entry in the app looks old, treat it as a starting point and check the chain’s current menu.

Pick one chain meal you eat and compare the app’s number with the chain’s own menu. Does the entry say who published it?

Do delivery apps, pubs and coffee shops show calories?

Delivery apps do, for food that is in scope. The English rules cover food sold on a website or mobile app, so the business running the app has to display the calories of food that qualifying businesses offer, whatever its own size. A takeaway you order from is a better source than a similar-looking dish in a database.

Pubs are the gap. The same guidance exempts alcoholic drinks over 1.2% ABV, so a menu can give a burger’s kcal and say nothing about the pint beside it. The NHS puts a pint of 5% beer at up to 222 kcal. A 175 ml glass of 12% wine is up to 158 kcal, and a 50 ml double of 40% spirits is 100 kcal. A pint and a glass of wine add up to 380 kcal, or 19% of the 2,000 kcal reference. Log drinks by volume and strength if the app allows it. A line that just says “beer” hides a gap that size.

Coffee has its own wrinkle. Some boards can’t fit every milk. The guidance gives the example of showing calories for semi-skimmed and pointing customers to a fuller menu for the rest. The number on the board may not be the number in your cup. Check that the app’s coffee entry lets you choose the milk.

What does free mean in a UK calorie counter app?

Mostly a trial dressed as a tier. 10 of the 15 trackers I checked have a free tier, and what the paid screens add differs a lot, so I keep the free calorie counter app comparison open for what each free tier drops. 13 of the 15 declared tracking on their App Store page, and the same 13 ask their questions before they show a price. So open the UK page in the App Store first, read the privacy box, the trial length and the subscription price in pounds, and only then make an account.

Speed is the one thing I’d pay for, and I’d test it first with three packs from your cupboard. Scan each, then compare the per 100 g energy with the label. And if you’d rather not subscribe at all, the trade-offs of a calorie counter app with no subscription are worth reading first.

What does a ten-minute trial of a UK calorie counter look like?

Run the same script on every app, on the free tier or the trial. Set a timer, because the point is to find out fast.

Minutes	Check	It passes if
0–2	Search the nine words from the table above	each UK word finds the food without a translation
2–5	Scan three packs from your cupboard	each returns the label’s per 100 g energy and lets you type your own grams
5–6	Enter 12 st as your weight	it shows 168 lb or 76.2 kg
6–8	Pick one chain meal and open the chain’s own menu	the app’s kcal matches the menu
8–10	Open the UK App Store page	the trial length, the price in pounds and the privacy box are readable before you make an account

For the scan step, pick one pack from a UK brand and one from abroad. GS1’s prefix list gives 500 to 509 to GS1 UK, so a barcode that starts with 50 was registered there. A brand can register elsewhere. Use the prefix only to be sure you tested both kinds. If a scan slips, where a barcode scan goes wrong covers the usual four places.

A fail on the first two rows ends the trial, because no review fixes a database that doesn’t know your shop. I stop at the first app that passes all five and use it for two weeks before I judge it.

The app that owns this blog charges a subscription, so discount my view of it. For a UK reader it has two gaps: it is a subscription after a 7-day trial, and it has no watch app.

Calsa lets you choose kcal or kJ and kg, lb or stone, scans UK products, and lists chain dishes with the numbers each chain publishes.