Munen computes a daily zone from five signals: night use of your flagged apps, time in those apps, how many times you open them, intensive sessions, and how you handle the pause itself. Each has a fixed published weight. They sum to a load between 0 and 1, and the load maps to a zone between 1 and 5. No model, no training, no black box.
This page prints the whole thing. If you are going to let an app adjust how hard it is to open Instagram, you should be able to read the arithmetic.
The five signals and their weights
| Signal | Weight | What it counts | Severity starts | Severity maxes |
|---|---|---|---|---|
| Night use | 32 percent | Minutes in flagged apps between 22:00 and 07:00 | 5 minutes | 30 minutes |
| Time in flagged apps | 26 percent | Daily minutes in the apps you chose | 60 minutes | 180 minutes |
| Opens | 16 percent | How many times you opened those apps | 15 opens | 60 opens |
| Intensive sessions | 14 percent | Sessions where you used most of your access window | 1 session | 4 sessions |
| Pause handling | 12 percent | How often you push past the pause, and for how long | see below | see below |
Every signal is normalized the same way. Below the floor it contributes zero. Between floor and ceiling it ramps in a straight line. Above the ceiling it is capped at full severity. So the fifth hour in TikTok does not count more than the third.
Note what is not on the list. Total screen time is not a signal. Your productivity apps, your maps, your email, your camera: none of them move your zone. Only the apps you flagged as distracting are ever read.
How the five become a zone
Multiply each signal's severity by its weight, add them up, and you get the load.
| Load | Zone |
|---|---|
| 0.15 or less | 5, Flow |
| 0.15 to 0.35 | 4 |
| 0.35 to 0.55 | 3 |
| 0.55 to 0.75 | 2 |
| Above 0.75 | 1, Pause |
Three adjustments sit on top of that mapping, and each exists to fix a specific failure.
A dead band of 0.05 at every boundary. If your load hovers right on the line between two zones, the zone does not flip back and forth day to day. It stays where it was.
A cap of one zone per day. Your zone can move at most one step from the zone you actually saw yesterday, in either direction. Three good days in a row take you from 2 to 5. One bad day cannot take you from 4 to 2.
Productive use credit. If you barely engaged with the flagged apps at all on a given day, meaning two or fewer interactions with the pause, the weight of your screen time is cut to 40 percent of its severity. A heavy phone day spent working is not the same as a heavy phone day spent scrolling, and the engine says so.
The two rules that bypass the arithmetic
A weighted sum has a known weakness. It averages, and averaging can hide a genuinely bad pattern behind an otherwise calm day. So two explicit rules can subtract a zone directly.
Heavy night use. Thirty minutes or more in flagged apps between 22:00 and 07:00 subtracts one zone. This is covered in full in what late night scrolling costs you the next morning.
Severe pause resistance. Either six or more pushes past the pause on a day where you respected it less than 30 percent of the time, or 45 minutes or more of total time inside those access windows. Whichever fires, it subtracts one zone, and only one. Both describe the same behavior, so they are never allowed to stack.
The 45 minute figure is not arbitrary. Hunt and colleagues, in a 2018 randomized trial at the University of Pennsylvania with 143 undergraduates, found that limiting social media to roughly 30 minutes a day over three weeks reduced loneliness and depression. Forty-five minutes is about one and a half times that target, deliberately unblocked. The paper is "No More FOMO: Limiting Social Media Decreases Loneliness and Depression", published in the Journal of Social and Clinical Psychology.
What an intensive session actually is
This one is worth explaining because most apps get it wrong. An intensive session is not a fixed number of minutes. It is relative to your own access window.
If your zone gives you a 5 minute window, using 4 of those minutes is intensive. If your zone gives you 20, using 4 minutes is not. The threshold is 80 percent of whatever your current window is, with a floor of 3 minutes.
An absolute threshold would have penalized calm users for behavior that is normal at their allowance, and let restricted users off the hook for exhausting theirs. The relative one asks the same question of everyone: did you use almost all of what you had.
Common questions
Is any of this sent to a server? No. The zone is computed on the device, in both the Dart and Swift sides of the app. Anonymous product analytics are sent. The AI features send what you write plus a summary of your week's numbers, and only when you use them.
Can I see my own numbers? Yes. The zone explanation in the app names the dominant signal for the day. The progress screen shows your zone history.
Can I override the zone? Yes. You can set it yourself once a day on the free plan, and roughly every four hours on Premium. A manual choice wins for that day.
Why are the weights those numbers and not others? Night use carries the most because it has the strongest evidence behind it. Pause handling carries the least because it is the noisiest signal and the most affected by a single unusual day. The rest sit between.
Do the weights ever change? They are constants in the code and change only in a release. When they do, they change on both the Dart and the Swift side at once, because the engine is implemented twice so it can run at midnight without the app being open.
The short version
Five signals, fixed weights, published thresholds, a load between 0 and 1, and a zone between 1 and 5 with a one step per day speed limit. That is the whole engine. If you want to see what it produces in practice, compare it against apps that apply the same setting every day in Munen vs one sec.