Huesy
A metal machine on a wall pouring a broad stream of rainbow-coloured paint. On the left a golden floor plan marked 5.60 and 4.20; on the right a panel reading 125.4 m², 7.3 litres, two tins and a tick.
Paint calculator

Never too little. And certainly never too much.

Enter the measurements of your room. Huesy tells you which tins to put on the counter — the ones with the least left over. Half a litre short and you top up. A tin left over, you never get rid of.

Free, no account. The app is not in the stores yet — these buttons will work the moment it is.

Why

Too little is a trip to the shop. Too much is money thrown away.

Those two do not weigh the same, and yet everyone errs the wrong way in front of the shelf. A litre short and you are back in the shop half an hour later. Annoying, and then it is sorted.

A tin too many is not. Opened or not, you cannot take it back. It sits in the shed for two years, it thickens, and then you carry it to the tip. So Huesy does not round up “to be safe” — it looks for the tins that come closest. A living room of 5.60 by 4.20 by 2.50 metres, two doors, three windows, two coats of matt wall paint:

42.8 m² what actually gets painted, doors and windows already deducted
7.3 litres two coats, with five percent spare for spills and touch-ups
1 × 5 L
+ 1 × 2.5 L
7.5 litres together — 0.2 left over, and no tin that stays behind

What the shop sells you for 7.3 litres

1 × 10 L € 0 · 2.7 L left over
2 × 5 L € 0 · 2.7 L left over
3 × 2.5 L € 0 · 0.2 L left over
1 × 5 L + 1 × 2.5 L € 0 · 0.2 L left over

Four combinations, the same wall. The difference between the first and the last is € 0 of paint you will never use. Huesy picks the bottom one — and where the surplus ties, the one with fewest tins, because carrying two beats carrying three.

what goes on the wall what ends up in the shed Change the price to what you pay per litre.

Work it out for your next room instead of your last one.

Do the sum

What is left of your last paint job?

Go and count the tins in your shed. Half-empty ones from the kitchen, from the previous owners, from the room you did two years ago. Every one of them was bought thinking “better one too many than one short”.

€105

is drying out in there. Change the figures to what you actually paid — what paint costs varies by brand and by shop, so that number should come from you, not from us.

What it does

It does not just calculate. It tells you what to buy.

Tins, not litres

Seven point three litres does not exist in a shop. Huesy looks for the combination with the least left over, and where that ties, the fewest tins. Not a single ten-litre tin because the sum is easier — that is nearly three litres you will never use.

Doors and windows come off

Automatically, at 1.7 m² per interior door and 1.5 m² per window. Got a bay window or a sliding door? Change the figure and everything recalculates.

Colours that actually sit together

Pick a base colour and get three combinations that work, with the split included: which colour on the large surface, which on the woodwork, which as an accent. The maths runs on how the eye sees, not on how a computer stores colour — which is why a Huesy palette looks level instead of lopsided.

The whole shopping list

A materials list that knows which room you are standing in: mould cleaner for the bathroom, degreaser for the kitchen, a foam roller the moment gloss is involved. Plus how many rolls of tape and how many square metres of dust sheet.

When the second coat can go on

Enter the temperature and humidity and you know when to carry on. Set a reminder and you do not have to go and feel the wall. Recoating too early is the most common mistake, and the most expensive one.

Everything stays on your phone

No account, no sign-in, no server holding your rooms. Your projects live on your device and nowhere else. The button to wipe all of it sits right there in the settings.

Inside the app

Five screens, and no menu to get lost in.

Swipe through to see how it looks.

The calculator screen: room name, room type, and length, width and height on one row.
Measurements in, answer always in view
The colour screen with a grid of swatches and a complementary palette with its percentage split.
Palettes that hold together
The projects list with two saved rooms, showing their area and litres.
Your rooms in one place
The guide, with articles about colour, each headed by a strip of swatches.
The guide, for when you are unsure
The settings screen, leading with which version you have, then theme and language.
Everything where you expect it

Five measurements, half a minute, and you know what goes on the receipt.

Price

One payment. No subscription.

You do not decorate every week. So you pay once here, and then never again.

Free

€ 0

  • Unlimited calculations
  • Two saved projects
  • Shopping list and drying times
  • The guide and the base palettes
  • With ads

Ad-free

€ 2.99 one-off

  • All ads gone
  • Everything else stays as it is

Huesy Pro

€ 4.99 one-off

  • Ad-free
  • As many saved projects as you like
  • Your shopping list as a PDF, to take with you
  • Extra colour palettes
Questions

What people want to know

How much paint do I need per square metre?

Wall paint covers roughly 8 to 10 m² per litre, per coat. Ceiling paint around 8, wood gloss around 13. On a rough or absorbent surface you will not reach that — allow about a third more. Huesy uses these figures and lets you change them to whatever your tin says.

How many coats do I need?

Two is normal. One is enough only when touching up in the same colour. For a strong colour change — dark to light, say — a primer or a third coat is often needed.

How long should paint dry between coats?

Water-based wall paint: about four hours at 20 °C and 60 % humidity. Wood gloss: sixteen. Cold and damp slow that down considerably, and below 8 °C water-based paint bonds poorly. Huesy adjusts the drying time to your conditions.

Should I deduct doors and windows?

Yes, as soon as it is more than a small window. An interior door counts for roughly 1.7 m² and an average window for 1.5. With one door and one window that already saves more than three square metres.

Does it work for a sloped ceiling or a bay window?

For a rectangular room Huesy takes the perimeter times the height. If you have a sloped roof or a bay, measure the area yourself and enter it directly — one tap on “I know the m²”.

Why only five percent margin?

Because something always goes wrong — spills, touch-ups, a patch that needs rolling twice — but not so much that it warrants another tin. Allowing more sounds safe and produces exactly what you do not want: paint left over. Run short and you top up. You can change the percentage in the settings, or set it to zero.

Does it work without internet?

Yes. The calculation happens on the device itself, so it works in a basement or in a house where the wifi is not connected yet.

Do I need an account?

No. No account, no sign-in, no email address. Everything stays on your device — more about that in the privacy policy.

Before you head to the shop.

Entering five measurements takes half a minute. That is less than the queue at the mixing machine, and it saves you a tin you never open.

Free. No account. No subscription.

2005Since

Huesy is an app by Noappy, the app arm of Nonius BV in Dendermonde, Belgium. We have been building software since 2005 for people who use it to get work done, not to look at.

You can tell: no account, no profile, no server holding your rooms. A question, or something that does not add up? Write to info@nonius.be and you will hear back from someone who built the app.

Never too little. And certainly never too much.Free, no account, no subscription.