Lawn lime calculator
Lime rates come from a soil test, not a guess. Enter the requirement on your test report and the strength printed on the bag to see how much lime to buy.
Estimates round up. Check product labels and supplier figures before ordering.
Liming materials and maximum rates
| Material | Calcium carbonate equivalent | Speed | Max per application (lb/1,000 sq ft) |
|---|---|---|---|
| Ground limestone | 70-95 | Slow | 50 |
| Dolomitic limestone | 70-95 | Slow | 50 |
| Pelletized limestone | 70-95 | Fast | 50 |
| Hydrated lime | about 140 | Fast | 20 |
| Burned lime | about 180 | Fast | 10 |
How it's calculated
A soil test reports how much pure calcium carbonate your lawn needs to reach a healthy pH. Lime on the shelf is weaker than pure calcium carbonate, so the calculator divides the requirement by the bag's calcium carbonate equivalent (CCE).
Lime per 1,000 sq ft = requirement / (CCE / 100)
Total lime = lime per 1,000 sq ft x area / 1,000
Applications = lime per 1,000 sq ft / 50, rounded up
Example: a 5,000 sq ft lawn with a requirement of 50 lb per 1,000 sq ft and a 90% CCE lime needs 50 / 0.9 = 55.6 lb per 1,000 sq ft. That is 278 lb in total, or seven 40 lb bags. Because it is above 50 lb per 1,000 sq ft, split it into two passes of about 28 lb, months apart.
The 50 lb maximum and the product table follow Ohio State University Extension guidance. Do not apply lime without a soil test, since too much can push soil pH too high.
What you'll need
- Pelletized lime
- Soil test kit
- Broadcast spreader
- Lawn core aerator rental
Common questions
How much lime do I need per 1,000 square feet?
It depends on the soil test. A common rate for ground limestone is about 50 lb per 1,000 square feet, and the soil test report gives the exact requirement.
When is the best time to lime a lawn?
Spring or fall, when rain is common, is recommended because rain moves lime into the root zone. Avoid wilted or frost-covered turf.
What does calcium carbonate equivalent mean?
It is the percent of the product's liming strength compared with pure calcium carbonate. A bag rated 90 is 90% as strong, so you need more product than the soil test number.
Can gypsum replace lime?
No. Gypsum barely changes soil pH, so it is not a liming material.