One number for "am I in ketosis?" — plus the Carb Tank, hidden-carb warnings, and the Stats screen behind it.
Most of KetoLens exists to feed one number: the Ketosis Battery. It's our best estimate of how likely you are to be in ketosis right now, and it sits front and centre on your home screen. Here's what it means and what moves it.
The home screen stacks four things:
Tap View details → on the battery to jump to the full Stats screen.
The battery runs from 0 to 100. Low means we're confident you're not in ketosis; high means we're confident you are. The colour and the status label move with it:
The battery is an estimate from your food log, not a measurement of your actual blood ketones. Everyone's metabolism is different. Want certainty? Log a ketone reading — a real measurement overrides the food-based guess.
The score looks at roughly the last 72 hours of eating, with recent meals weighted more heavily than old ones. In plain terms:
Low net carbs · a high share of fat in your calories · ketone readings in the 0.5–3.0 mmol/L range · logging consistently within your goal day after day · a genuine fast of 14+ hours.
Net carbs over your goal · flagged hidden carbs · alcohol in the last 48 hours · very low ketone readings · long stretches with nothing logged.
New accounts (or days with very little logged) show Early Estimate or Rough Estimate instead of a confident verdict — the battery is honest about not having enough to go on yet. Log a few meals and it firms up.
Silence isn't evidence. Stop logging and the score decays — roughly halving for each quiet day — and the battery fades to a grey "outdated" state rather than pretending everything's fine. The Score Breakdown shows the deduction as an Inactivity Decay card, so the drop is never a mystery. Two things pause it: a fast the app can credit (next section), or a logged ketone reading — a real measurement always beats an assumption. (There's an in-app FAQ that answers this and more — tap FAQ on the Stats screen.)
Skipping breakfast is doing real metabolic work, and the battery pays for it. Go 14+ hours since your last proper meal and a Fasting card appears in the Score Breakdown with a small bonus — starting at 2 points and growing to 6 by the 24-hour mark, because a full-day fast earns more than a late start.
While a credible fast is running, the inactivity decay above waits — you won't be paid a bonus and charged a penalty for the same empty stretch.
The Carb Tank is the simple one: net carbs you've eaten today vs your daily goal, shown as "61 / 50g" with a bar that fills as you log.
It resets at midnight, your time, and follows whatever carb goal you set in Settings.
Tap Stats in the bottom bar (or View details on the battery) for the full story behind the number. Switch ranges at the top — Today, 7D, and (on Pro) 30D and Custom.
The Score Breakdown tells the story as a series of cards — Carb Intake, Fat Ratio, Hidden Carb Warnings, Ketone Reading, Consistency, Alcohol Brake, Fasting, and (if you've gone quiet) Inactivity Decay. Only the ones that actually applied show up. Each shows its points and a one-line reason — "Your carb intake is moderate at 48g daily-equivalent — under your 50g goal, but getting close" — and tapping a card opens the full working. No black box.
Pick a longer range and you get the bigger picture: days in ketosis, your current and best streak, a daily score heatmap, and a Battery Score History chart with the ketosis threshold marked.
Below that: a Net Carb Trend line against your keto target, and a Week-over-Week comparison so you can see whether this week beat the last — average score and days in ketosis, with the change called out.
Top Carb Foods ranks the items adding the most carbs over the period — useful for spotting a habit. If you log ketones, your readings are summarised here too. The deepest insights (carb thresholds, meal timing, correlations) are a Pro feature.