How does scanning work and how do I correct a result?
Kairo logs meals in four ways: by photo, by description (text or voice), by barcode, and by a photo of a restaurant menu. Every result is an estimate you can change: open the meal, tap "Edit" and adjust the name, calories, macros or quantity, or describe in one sentence what was different.
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Correct a result
- Tap the meal in your day to open it.
- Tap "Edit". The name, calories, macros and quantity become input fields.
- Change the values directly or tap "Adjust by description" and write what was different, for example "a bit more cheese" or "2 portions in total". Kairo's AI then re-estimates the values from your description.
- If you change the name, Kairo asks whether to recalculate with the new name ("Re-analyze") or only rename the entry ("Just rename").
- Confirm with the checkmark at the top. To remove a meal, open the ⋯ menu and choose "Delete".
How does the photo scan work?
Tap the scan button in the bottom bar and choose "Scan food". The camera has three modes: "Photo", "Barcode" and "Menu". In "Photo" mode you take a picture of your meal; you can also pick an image from your photo library.
The photo is sent through Kairo's server to the Google Gemini API. The model identifies foods and ingredients, estimates quantities and returns calories, protein, carbohydrates and fat. Kairo uses the paid API: your photos are not used by Google to train AI models; Google keeps submitted data for up to 30 days for abuse monitoring and then deletes it. For branded products and restaurant dishes Kairo additionally looks up nutrition values on the web. Only the recognised product or dish name is sent, no image and no user identifier.
Inside a meal, "How I did the math" shows how Kairo arrived at the numbers and "Sources" shows what they are based on.
How do I describe a meal without a photo?
Choose "Describe" in the scan button's menu and write what you ate, for example "a medium egg with a slice of whole wheat bread and butter". You can also speak: speech is converted to text on your iPhone, and no audio leaves the device.
Without a stated amount, Kairo's AI works with typical portion sizes. The more precisely you name quantity and brand, the better the estimate.
How does the barcode scan work?
In the camera's "Barcode" mode Kairo reads the EAN or UPC code on a package and retrieves the product name and nutrition values from the open database Open Food Facts. Only the barcode number is transmitted. Barcode lookups are unlimited without a subscription.
If the database does not know a product, or has no nutrition values for it, Kairo's AI analysis steps in based on the photo. That AI analysis then counts like a photo scan; see Scans without a subscription.
What is the menu scan?
In the camera's "Menu" mode you photograph a restaurant menu. Kairo reads the dishes, you select the ones you want to log, and add them. If nothing is recognised, a sharper photo of the menu helps.
Can I set whether Kairo leans high or low when it estimates?
Yes. In your profile under "My Goals" you will find "Calorie Bias" with five levels from "Underestimate More" to "Overestimate More". It only applies when Kairo has to estimate, that is, when it cannot find exact nutrition data. "No Bias" is the most accurate setting.
If a result is wrong, you can report it from the meal's ⋯ menu with "Give feedback".
Related articles
- Getting started & scanning
What is Kairo and how do I get started?
Kairo is an AI calorie tracker for iPhone: photograph a meal, read off calories and macros. How to set up the app and run your first scan.
Read the article - Getting started & scanning
How accurate are Kairo's calorie numbers?
Kairo's numbers are AI estimates. Benchmark of 2026-06-16: 16 of 16 cases passed, about 3.5% mean error on branded items, 10–12% on generic whole foods. Re-run 2026-08-25: 21, 23 and 22 of 23 passed.
Read the article - Subscription & billing
What can I use without a subscription, and what needs one?
What you can use in Kairo without a subscription: three AI analyses per account (photo, describe, menu scan, barcode AI fallback) and unlimited barcode lookups. From the fourth AI analysis on you need a subscription.
Read the article
Didn't find your answer?
Email support at support@kairocalories.com, in English or German. Kairo is operated by Centaurio UG (haftungsbeschränkt), Hofheim am Taunus, Germany.
Common questions
Does a correction use up another scan?
No. If a meal was logged with one of the three AI analyses without a subscription, re-analyzing it and adjusting it by description remain possible for that meal without a subscription. Only new meals count.
Are my food photos used to train AI?
No. Kairo uses the paid Google Gemini API; Google does not use the data to train AI models and deletes it after 30 days at most.
Can I enter values entirely by hand?
You can overwrite the name, calories, protein, carbohydrates, fat and quantity of any meal by hand: open the meal, tap "Edit", change the values.
Kairo reads your meal from a photo and shows calories and macros. For iPhone, with Apple Health and Apple Watch.
Download on the App Store