I’m Sam, and I build the calculators on this site.
It started with a paint job. I was repainting our living room, pulled up three “how much paint do I need” calculators, and got three different answers. None of them showed their work, none let me subtract the doors and windows, and one quietly assumed a single coat. So I wrote my own, and then I kept going.
That is what this site is now: home and DIY project calculators I actually trust. There are nine so far, covering paint, tile, flooring, concrete, mulch, drywall, wallpaper, fencing, and gravel, plus a set of plain-language guides. The stuff you need a number for before you drive to the hardware store, where guessing wrong means a second trip or a half-used pallet in the garage.
How I build these tools
Every calculator shows its math. You see the formula and the constants it used, not just a result, so you can check it against your own measurements. I would rather you trust the number than take it on faith.
I verify the constants before they go in. Paint coverage, concrete bag yields, how many square feet a yard of mulch covers at two inches deep: these are real, published figures from manufacturer specs and industry sources, and I use the conservative end so you do not come up short. When a number genuinely varies by product or region, I say so and tell you what I assumed.
These are estimates for planning, not engineering specs. For anything structural, check with a professional. I will always tell you where a calculator’s assumptions stop and yours need to start.
Get in touch
If a calculator gives you a number that looks off, or there is a tool you want that is not here yet, I want to know. You can reach me at contact@better-courses.com or through the contact page.
– Sam
Built and maintained by Sam Walsh. Last updated July 2026.