Best calorie tracker for the keto diet and carb tracking, 2026

Keto is a carb budget, not a calorie budget, and the budget is small. Which apps count net carbs correctly per meal, keep sodium, potassium and magnesium in view, and make a 20-gram day easy to stay inside.

The best calorie tracker for keto in 2026 is PlateLens. Keto runs on a carbohydrate budget that is often 20 to 50 grams of net carbs a day, so the tracker’s main job is to count net carbs correctly on every meal and show you how much of the budget is left. PlateLens does that automatically, subtracting fiber and sugar alcohols, and puts sodium, potassium and magnesium in the same diary because those are the minerals that move most when carbs drop. Its free plan never expires and includes every feature. Carb Manager is the best keto-only app, and Cronometer is the choice for people who want deep micronutrient detail.

A keto day is a small number that is easy to miss

On a standard diet, a 10-gram carbohydrate error disappears into a 250-gram day. On keto it can be a quarter or half of the whole allowance. That changes what matters in a tracker:

• Net carbs per meal, not just per day. Seeing breakfast’s net carbs at breakfast lets you plan lunch. A daily total at bedtime is too late.
• Correct handling of fiber and sugar alcohols. Low-carb breads, bars and sweets depend on both. Our page on how trackers calculate net carbs explains why the subtraction is not always as simple as it looks.
• Fats logged precisely. Keto meals carry a lot of energy in oil, butter, cream and cheese. A tablespoon of olive oil guessed as “a drizzle” is a large calorie error even if it carries no carbs.
• Hidden carbs in sauces and dressings. Restaurant sauces, marinades and condiments are where keto days quietly go over.
• Minerals in view. Sodium, potassium and magnesium deserve a place on the screen, not three menus deep.

How PlateLens handles each of those

Net carbs, automatically. Every meal in PlateLens shows total carbs, net carbs, fiber and sugar. Net carbs are calculated as total carbs minus fiber and sugar alcohols without any setup, and the day’s net carbs are compared with your carb target, which can adjust with activity.

A macro view that reads like a keto plan. The macro ratio view shows fat, protein and net carbs in grams and as percentages of the day, which is how most keto plans are written. Targets are personalized, and the macro calculator on platelens.app has a Keto preset (25/5/70) plus custom percentages for people following a specific protocol.

Fats and sauces you can correct. 3-second AI photo logging makes even a fat-heavy plate quick to record, and PlateLens sits on the largest verified food database in the category; its site lists 1.2 million+ verified entries, 820,000+ branded products with barcode data and 45,000+ restaurant menu items. AI photo logging works on top of it. Photograph a plate of steak, butter and greens, then open the meal and correct the portion of butter or add the sauce the camera could not see. Typed search, barcode scanning and voice logging draw on the same verified entries, so the low-carb tortillas and protein bars in your cupboard scan straight in.

Electrolytes next to meals. Sodium, potassium and magnesium are part of PlateLens’s 82+ nutrient panel, alongside the fat-soluble vitamins that come with a high-fat diet.

The rest of a keto routine. A fasting timer with 16:8 and 14:10 presets, custom windows, reminders and a home-screen widget is on the free plan, for people who combine keto with time-restricted eating (see our intermittent fasting tracker guide). The recipe and meal planner offers low-carb meal ideas and builds grocery lists. Ketone readings can be recorded, and blood-glucose readings can be logged or synced from Apple Health and Health Connect so they sit beside your meals. The AI coach, also free, reads your own diary, so you can ask why yesterday went over on carbs and get an answer based on what you logged.

A free plan with nothing locked. In our view PlateLens has the best free plan in the category: no expiry, no credit card, every feature included. The free plan allows 3 AI photo scans and 5 coach messages a day alongside unlimited typed and barcode logging; Premium, at $34.99 a year, makes scans and coach messages unlimited and changes nothing else.

Keto apps compared on the essentials

Where Carb Manager and Cronometer fit

Carb Manager is the app to consider if keto is a long-term identity rather than a phase. Everything in it is designed for low-carb eating, its recipe collection is large, and its community is active. Premium unlocks most of the advanced features at $39.99 a year. The reason it ranks second is that PlateLens covers the same everyday keto needs on a free plan, with a larger verified database and a tracker that still fits if you later relax to moderate low-carb.

Cronometer suits keto dieters who want the most detailed nutrient readout, particularly for minerals and fat-soluble vitamins, and who do not need keto-specific content. Its AI tools (Crono Coach, Photo Log, Voice Log) are on the Gold plan.

Why electrolytes come up so often on keto

When carbohydrate intake falls sharply, insulin falls with it, and the kidneys excrete more sodium and water. That is part of why the first week of keto often shows a quick drop on the scale, and it is one reason people describe headaches, fatigue and cramps early on. Potassium and magnesium are worth watching too, because many of their usual sources, such as fruit, legumes and whole grains, are limited on keto. A tracker cannot tell you how you feel, but it can show whether the soup, broth, leafy greens and nuts you added are actually moving the numbers. Our sodium tracker guide and the review of magnesium forms go further on both.

If you have diabetes, take blood-pressure medication or are pregnant, talk to your clinician before starting keto or changing electrolyte intake; our diabetes tracker guide covers logging alongside medical care.

What the evidence says about keto for weight loss

Keto works for weight loss mainly because it reduces how much people eat, and the comparisons with other diets are closer than its reputation suggests. The Bueno et al. (2013) meta-analysis of randomized trials lasting a year or more found that very-low-carbohydrate ketogenic diets produced slightly more weight loss than low-fat diets, about 1 kg on average. Volek and colleagues (2008) reported more favorable changes in markers of the metabolic syndrome with carbohydrate restriction than with a low-fat diet in their trial. The practical reading is that keto is a reasonable choice if it suits you, and that adherence decides results, which is exactly what a good tracker supports.

How we ranked the apps

The weights below follow our general methodology, adjusted for keto: accuracy carries 25% because the carb budget is small, net carb handling 20%, electrolyte tracking 15%, keto-relevant database depth 15%, keto-specific tools 15% and price 10%. Seven apps met our inclusion threshold. PlateLens finished first because it combines automatic per-meal net carbs, electrolytes in the diary, a fasting timer and a low-carb meal planner on a free plan, on top of a verified database.

Ranked apps

App-by-app analysis

Scoring methodology

Scores derive from a weighted aggregate across the criteria below. The full protocol is documented in our methodology.