Lime Calculator
Calculate how many pounds of lawn lime you need to raise soil pH, based on 50 lbs per 1,000 sq ft, plus total cost.
How this calculator works
Lawn lime is a soil amendment applied to raise pH in acidic soil. This calculator uses a coverage rate of 20 square feet per pound, which corresponds to the common 50 lbs per 1,000 square feet lawn-maintenance rate.
Formula: Lime (lbs) = Lawn area (sq ft) ÷ 20 sq ft per lb.
Worked example
A 50 ft × 20 ft lawn area (1,000 sq ft):
- Lime needed: 1,000 ÷ 20 = 50.00 lbs
- At $0.12/lb, that’s $6.00.
Coverage reference
| Lawn area | Lime needed |
|---|---|
| 25 × 10 ft | 12.50 lbs |
| 50 × 20 ft | 50.00 lbs |
| 100 × 40 ft | 200.00 lbs |
How to measure your lawn
Measure the length and width of your lawn in feet and multiply for total square footage, treating differently-sloped or differently-shaded sections as one combined area unless a soil test shows their pH actually differs. Get an inexpensive soil pH test before applying anything — it takes the guesswork out of how much, if any, lime your lawn actually needs.
Frequently asked questions
Should I test my soil before applying lime?
Yes — always test soil pH before liming rather than applying it as routine maintenance. Lime raises pH, and if your soil isn't actually acidic, adding it can push nutrients out of the range plants can absorb, doing more harm than the problem it was meant to fix.
How much lime does a lawn typically need?
This calculator uses a common rate of 50 lbs of lime per 1,000 square feet, equivalent to 20 square feet of coverage per pound. That's a general lawn-maintenance rate — a soil test result showing more severe acidity may call for a heavier application, sometimes split across two applications months apart.
Pelletized or powdered lime — which should I use?
Pelletized lime is bound into small granules that spread evenly through a standard broadcast or drop spreader and won't blow away, making it the practical choice for most homeowners. Powdered (ground) lime reacts with soil faster but is dusty, harder to spread evenly, and more prone to drifting in wind.
How long does it take lime to change soil pH?
Lime works slowly, typically taking several months to fully react with the soil, which is why fall is the most commonly recommended application window — it gives the lime all winter to break down before the growing season. Don't expect visible results within days or weeks.
Is there a difference between lime for lawns and lime for garden beds?
The material is often the same (calcitic or dolomitic agricultural lime), but application rates differ by soil test results and by what's growing — vegetable beds and ornamental plantings frequently have different target pH ranges than turfgrass, so don't apply a lawn rate to a garden bed without checking the numbers first.
Estimates only. Verify quantities with your supplier before purchasing.