Free Garden Calculators That Give You a Straight Answer
Every tool takes your numbers and returns exactly what to buy, sow, or plant — nothing else.
Raised Bed Soil Calculator
Exact cubic feet, bags needed, and cost estimate for any bed size or mix recipe.
Seed Starting Calculator
Count back from your last frost date to find the right indoor sowing week.
Plant Spacing Calculator
Get exact row and in-row spacing for any crop in any bed size.
Succession Planting Calculator
Schedule repeat sowings so you always have something ready to harvest.
Germination Rate Calculator
Turn a germination test into exact seed quantities to sow.
Compost Ratio Calculator
Balance browns and greens to hit the right C:N ratio for fast decomposition.
Why RootCalcs?
Real math, not round estimates
Every formula is documented and explained on the calculator page. You can verify the arithmetic yourself.
No login, ever
No account, no email wall, no paywall. Open the calculator, enter your numbers, get your answer.
Works in the garden
Designed for a small screen with one hand free. Fast, readable, zero distractions.
Get the free planting-day checklist
Everything you need before seeds go in the ground — sent once, no spam.