indoorcalc.com.au is a small, free collection of calculators for indoor projects — paint, flooring, tiles, wallpaper, air conditioning, and whatever else comes up when you're renovating a room.
Why this site exists
Most of the renovation calculators online are built for the American market. They ask for square feet and gallons, they reference products that aren't sold here, and they assume you're buying paint in quarts. None of that matches what a Bunnings, Beaumont Tiles or Harvey Norman is actually quoting you.
When your tin says "covers 14 m² per litre" and you're standing in a 4.2 × 3.6 m room, you don't want to be converting gallons and square feet in your head. So every calculator here works in the units on your invoice: square metres, litres, millimetres.
What we're trying to get right
- Metric first. Not metric as an afterthought — metric as the default, because you're standing in an Australian home.
- Fast, not flashy. Type a few numbers, get the answer, close the tab. No email wall, no newsletter.
- Honest estimates. Every result includes a sensible waste margin and a reminder to check with your supplier.
- Phone-friendly. Most people work these things out with a phone in one hand and a tape measure in the other. The site has to work that way.
What we're not
We're not a supplier. We don't sell paint, tiles, flooring or anything else. There are no referral links to Bunnings, no affiliate deals with tile showrooms, no "get a free quote" buttons. The site is funded by display ads, which is why there's one advertisement on each page — that's it.
We're also not interior designers, builders or licensed tradespeople. The calculators are mathematical tools. Every one of them has a disclaimer saying "check with your supplier or tradie" — please actually do that, especially on bigger jobs where the wrong quantity costs real money.
Who's behind it
indoorcalc.com.au is an independent Australian-owned site. Feedback, corrections, and requests for new calculators are always welcome — get in touch if you've spotted something broken or there's a calculator you wish existed.
Accuracy and limitations
Every calculator is tested against published coverage rates and specifications from major Australian suppliers and manufacturers. Where values can vary (for example, paint coverage differs between budget and premium products), we document the assumptions in the calculator itself and let you adjust them.
Even so: results are estimates. Real-world variables — room irregularities, substrate condition, installer technique, regional product differences — mean your actual requirement can land 5–15% either side of the calculated figure. The rule of thumb is to order slightly more than calculated. Running short of tiles from the same batch is a far bigger problem than having a few left over.