Most accurate calorie tracker and the published evidence
No published study has tested all of these trackers against each other or named one most accurate among them. Available evidence combines the companies' descriptions of their food sources with studies of individual apps or small groups. This page covers Cronometer, MacroFactor, MyFitnessPal, Lose It, Cal AI, MyNetDiary, Foodvisor and TrueCal.
Compare food data sources and published accuracy research for eight calorie trackers, including where studies disagree and which apps lack a named test.
Three places a calorie total can go wrong
- The starting food record can differ from the food itself. Urban and colleagues found restaurant calorie declarations accurate overall, with substantial errors in some individual items.
- The entered portion can differ from the amount eaten. In Lucassen's lunch study, participants reported portions within 10% of measured intake in 31% of text estimates and 13% of image estimates.
- A photo estimate can miss the amount even when it identifies food. O'Hara's study of ChatGPT-4 found good food identification but poor agreement on the weight of medium and large meals. This was a chatbot study, not a test of the apps below.
Food databases and published tests for eight apps
Sources checked October 8, 2026. Company links describe their own data. Study summaries use published abstracts. A missing study means the dated PubMed search found no peer-reviewed test naming that app.
Cronometer had different results in two settings
Morello's 2025 athlete study reported good validity for Cronometer except for fiber and vitamins A and D. In Bayram and Ozturkcan's 2026 comparison, Cronometer was among the apps with the greatest discrepancies in energy and macros. That comparison used standardized menus for apps from the Turkish App Store, a limit the authors explicitly stated. The Cronometer review discusses those findings alongside the app's data sources.
MacroFactor's database description awaits an app test
The dated PubMed search for MacroFactor returned unrelated uses of the word and an author affiliation, with no study testing the app by name. MacroFactor says humans check submitted foods before public inclusion, which describes its process without supplying a research result for the app. See the MacroFactor review for the broader product assessment.
MyFitnessPal results depend on how records were collected
Evenepoel's team found strong energy correlation with Nubel after excluding implausible entries, while cholesterol and sodium correlations were weak. In Chen's independent logging study, participants omitted foods and underestimated energy and all macronutrients relative to dietary recalls. The MyFitnessPal research guide explains the individual study conditions, and the MyFitnessPal product review covers the app beyond those tests.
Lose It food entries and daily totals gave different answers
For individual foods, Lin and colleagues reported mostly excellent agreement between Lose It and the Nutrition Data System for Research. Using weighed daily records in UK app versions, Fallaize's team found lower carbohydrate, fat, fiber and sodium estimates than Dietplan6, but no significant energy difference. Our Lose It review follows these distinct measurements in more detail.
Cal AI's own claim has no named peer-reviewed test here
Cal AI's FAQ calls the app about 80% accurate, a company statement rather than a result from the PubMed search, which found no peer-reviewed test by name. The Cal AI evidence guide separates company claims from research. For a comparison of available logging options, see apps considered alongside Cal AI.
MyNetDiary was close to the reference in standardized menus
Bayram and Ozturkcan reported that MyNetDiary and FatSecret were closest to the reference records among the apps compared. Their abstract gives no MyNetDiary accuracy percentage and limits its findings to standardized menus. Rodder's curriculum study separately found significant correlations with SuperTracker. The MyNetDiary review distinguishes these nutrition comparisons from research about other aspects of the app.
Foodvisor's named study measured carbohydrates
Joubert's study found that Foodvisor underestimated meal carbohydrates by an average of 7.2 grams, with absolute errors above 20 grams in 30% of meals. Those results concern carbohydrates and do not establish a calorie accuracy percentage. Read the Foodvisor review for more about the app, or the AI calorie tracker comparison for other ways to log meals.
Check the food and amount before comparing totals
For a packaged food, put the app entry beside the package label. Compare the product name, serving amount and calories for that amount, using the nutrition label guide to read the fields. A comparison only makes sense when both amounts refer to the portion you ate.
For a database entry, open USDA FoodData Central and find the corresponding food and serving. It includes distinct data types such as Foundation Foods and Branded Foods. The guide to source information inside calorie apps explains where to look for the reference behind a logged item.
TrueCal attaches sources to estimated nutrition
TrueCal requires nutrition numbers to come from a source or the user, and its meal receipts display item sources. Its product explanation says estimates can be wrong and depend on supplied meal details. Manual calorie logging is free, while logging from a typed description, voice, a photo or a barcode, and macros, require Pro. The TrueCal comparison pages cover the available alternatives.