Paint Calculator

How to use Paint Calculator

1. Open Paint Calculator in your browser — it loads instantly and works offline once cached.
2. Enter your values in the input fields. Every field is labelled so you know exactly what to type.
3. The result updates automatically as you type — there is no "submit" round-trip to a server.
4. Adjust any input to compare scenarios and see how the outcome changes in real time.
5. Copy or note the result. Nothing you enter is stored or sent anywhere.

Why use Paint Calculator?

• 100% free with no limits, no sign-up and no watermarks.
• Private by design — your data are processed in your browser and never uploaded to a server.
• Fast and lightweight, with instant results even on a phone or a slow connection.
• Works everywhere — any modern browser on Windows, macOS, Linux, Android or iOS.
• Part of a full construction suite, so related paint tasks are one click away.

What people use Paint Calculator for

• Estimating how much paint a room needs.
• Working out coverage for a specific number of coats.
• Costing a decorating job.

Paint Calculator: limits and things worth knowing

• Typical emulsion coverage is 10-12 m² per litre per coat, but check the tin — coverage varies substantially by product and finish.
• Two coats is the realistic default. Bare plaster needs a mist coat first, and a strong colour change may need three.
• Porous and textured surfaces absorb considerably more than the stated coverage; new plaster can take half as much again.
• Deduct large openings but not small ones — the cutting-in around a window uses more paint per square metre than a flat wall.

Is it private and secure?

Your privacy is built in. Paint Calculator runs completely on your device, so whatever you enter stays in your browser and is never transmitted, logged or stored on any server.

Network activity: none. Nothing is sent and nothing is fetched. This tool makes no network request at all once the page has loaded — which is why it keeps working if your connection drops.

You do not have to take that on trust — our privacy proof page publishes the Content-Security-Policy that enforces it, lists every third party it permits, and shows how to verify the whole claim yourself.

Learn more

Why Browser-Based Tools Are Safer for Your Files — Most online converters upload your files to a server. Client-side tools don't. Here's why that difference matters for privacy.