wellness score Archives

The daily balance score in slotho is one number out of 100, built from three things: sleep, nutrition and activity. That part is easy to describe. The more interesting half is what it refuses to do — because most of the design decisions in it are refusals, and they are the reason the number is worth looking at.

The three factors in the daily balance score

Sleep — last night’s duration against your sleep target.
Nutrition — food and water together, because “did I fuel myself well today” is both of them, and one honest bar reads better than two half-empty ones.
Activity — active energy against your movement target.

Each is scored 0–100 on its own, and the overall number is the average of them. The band underneath is plain language rather than a colour alone: 80–100 on track, 50–79 mixed, below 50 needs attention.

Refusal one: a blank is a gap, not a zero

This is the one that matters most. If you did not log any food today, the nutrition factor does not score zero — it scores nothing, shows a dash, and drops out of the average entirely.

The alternative is what a lot of trackers do: treat an empty field as a failure, and hand you a 33 for a day in which you slept well, moved plenty, and simply did not feel like typing your lunch in. That number is not information about your day. It is information about your logging, dressed up as information about your day.

When only some factors have data the card says so directly — it reads “N of 3 factors” rather than “out of 100”, so a partial score is never mistaken for a complete one. And if nothing at all has been recorded, there is no score, because there is nothing to score.

Refusal two: it won’t judge your morning by the whole day’s target

An early version of this card had a real flaw. You would eat a sensible breakfast at nine in the morning, open slotho, and see 20 out of 100 — because 400 calories is indeed miles short of a 2,000 calorie goal. Technically true, completely useless, and quietly insulting at breakfast.

So targets are now pro-rated by how much of your waking day has actually elapsed. At 09:00 you are not expected to have eaten a day’s food. A sensible breakfast reads as on pace, and scores accordingly.

The waking day defaults to 07:00–22:00, not midnight to midnight — nobody should be judged for not having eaten a third of their calories by 08:00 just because a third of the clock has gone. And it is only a default: it is your waking day, so you can move it.

At the end of the day the pro-rating reduces to exactly the original curve, so a finished day is scored the same way it always was. The maths only bends while the day is still running.

Refusal three: it won’t let basal metabolism flatter you

The activity factor uses active energy only — the calories you burned by moving — not total expenditure. Total energy includes the very large number of calories your body spends keeping you alive while you sit still, and counting those would mean the score rises steadily through a day spent entirely on the sofa.

A score that goes up when you do nothing is not measuring anything.

Refusal four: it won’t treat every overshoot the same

The three factors are deliberately asymmetric, because the things they measure are:

Calories over the goal are penalised at any hour, measured against the full goal rather than the pro-rated one. Eating tomorrow’s calories by lunchtime is not “ahead of pace”.
Water has no overshoot penalty at all. Drinking more than your target is not a failure, unlike overeating, so the water score simply caps at 100.
Sleep is a band, not a point. Full marks anywhere inside an hour either side of your target — with the default 8-hour target, that is anything from 7 to 9 hours — falling off in a straight line to zero three hours outside the band. An ordinary night scores full rather than being docked for being eleven minutes short.

Sleep is also the one factor that is never pro-rated. Last night is already over by the time today starts; there is nothing provisional about it.

It knows when it is guessing

While the day is still running, the score is a running read against pro-rated targets, and it can still move. The card labels that state “So far today”, so a mid-afternoon number is never presented as a final verdict on the day.

It recomputes every minute, so the pace-adjusted number keeps up rather than going stale in your hand.

If you work nights

The waking day can wrap past midnight. Set it to 22:00–06:00 and a shift that starts on Tuesday evening and ends on Wednesday morning is scored as one day — the day it ends on, rather than being sliced in half by the calendar and scored as two bad ones.

Your targets, not ours

All four targets behind the score — sleep, calories, water and movement — are yours to set. The defaults are only defaults, and changing one re-scores your history against the new number rather than leaving old scores sitting next to a target they were never judged against.

Tapping the card opens the last month, scored by exactly the same rules, so “how am I doing lately” has an answer that is consistent with today’s.

What it is not

It is not a health metric, and it is written that way on purpose. It carries no medical framing and makes no claim about your health. What it summarises is narrower and more honest: how close to your own sensible targets was today.

The whole thing is computed on your device from data already in Apple Health. Nothing about your day is sent anywhere to produce it — see the slotho privacy policy for the detail. The daily balance card is part of slotho Pro.