I’m Sam, and I build the calculators on this site. Each one started with a project where the online tools gave me conflicting answers, hid their math, or just didn’t let me enter the numbers I actually had. So I wrote my own — tools that show every number, explain every assumption, and give you a result you can actually check.
Everything here is free, no sign-up required. Enter your measurements, get a number, go buy your materials.
Calculators
Paint Calculator
Enter room dimensions and ceiling height. I subtract doors and windows, add a second coat if you want one, and tell you how many gallons to buy — wall paint and ceiling paint separately.
Tile Calculator
Pick your tile size, enter the area, choose a waste factor for straight or diagonal lay. I give you a tile count and the number of boxes to grab, rounded up so you don’t come home short.
Flooring Calculator
Works for hardwood, laminate, and vinyl plank. Enter the room, pick your lay direction and board width, and I calculate square footage with the right waste factor for your pattern.
Concrete Calculator
Handles slabs, footings, and columns. Enter dimensions in feet and inches, I convert to cubic yards and tell you how many 60 lb or 80 lb bags you need — or how many cubic yards to order ready-mix.
Mulch Calculator
Enter the bed area and depth in inches. I output cubic yards and the equivalent bag count so you can compare buying in bulk vs. picking up bags at the garden center.
Drywall Calculator
Walls and ceilings separately. I count doors and windows as deductions, apply a waste factor, and give you a sheet count plus an estimate for screws and joint compound.
Wallpaper Calculator
Enter room perimeter and ceiling height, then the roll dimensions and pattern repeat. I account for the repeat when cutting each strip, so you don’t underestimate on patterned paper.
Fence Calculator
Span your fence line, choose post spacing and rail count, and I tell you how many posts, rails, and pickets to order — plus concrete bags for setting the posts.
Gravel Calculator
Works for pea gravel, crushed stone, and river rock. Enter area and depth, I give you cubic yards and tons — two units because suppliers use both and it helps to have both when you call.
Guides
- How to Measure a Room — the first step before you use any calculator. Covers rectangular rooms, L-shapes, and how to handle angled walls.
- How Much Paint Do I Need — a plain-language breakdown of coverage rates, primer vs. paint, and when one coat is actually enough.
- Tile Spacing and Layout Guide — grout joint widths, centering a layout so you don’t end up with a sliver at the edge, and why diagonal lay costs more tile.
- Concrete Bags vs Ready-Mix — the honest cost and labor comparison, and the project size where ready-mix stops being overkill.