Buy just enough.
Free calculators that turn your measurements into a shopping list: cans, bags, boxes and posts, rounded to what the store actually sells. No sign-up, nothing to install, and your numbers stay in your browser.
Paint calculator
Room size in, gallons and quarts out. Doors and windows are subtracted, the result is rounded up to what you can actually buy, and you won't be left with three spare cans.
Mulch calculator
Measure the bed, pick a depth, and get bags or bulk yards. Also works for topsoil, compost, pea gravel and rubber mulch.
Concrete calculator
Slab, pad or round footings: get the bag count for 80, 60 or 40 lb bags and the ready-mix amount to order, with a waste margin built in.
Flooring calculator
Add up to three rooms, choose your waste allowance and box size, and get the number of boxes to buy, not just square feet.
Fence calculator
Fence length in, a material list out: posts (with corners and gates), rails, pickets or panels, and bags of concrete for the post holes.
Why another calculator site?
Most calculators stop at square feet or cubic yards. JustEnough goes one step further: the number of 2 cu ft mulch bags, 80 lb concrete bags, flooring boxes or gallons and quarts to put in the cart, with a sensible waste margin and the formula shown so you can check it.