Lawn Care
Lime Calculator: How Much Lime to Raise Lawn Soil pH
Quick answer
To raise lawn soil one full pH unit, from 5.5 to 6.5, plan roughly 40 pounds of ground limestone per 1,000 square feet on sandy soil, 70 pounds on loam and 100 pounds on clay. Apply no more than about 50 pounds per 1,000 square feet at once on an established lawn, and confirm the rate with a soil test.
Lime raises soil pH, and most lawn grasses take up nutrients best in slightly acidic soil around pH 6.0 to 7.0. How much lime that takes depends on how far pH must move and on soil texture: clay and high organic matter soils resist change, so they need more. Enter your area, current and target pH and soil texture, and the calculator estimates pounds of lime, bags and how to split the job into safe applications. Treat it as a planning number: a lab soil test with a buffer pH reading gives the exact rate, and the MySoil Soil Test Kit is one mail-in option.
Lime calculator
Lime needed
Lime, soil tests and spreaders
Top matches update when you calculate.
Old Castle Pro Pelleted Dolomitic Limestone, 50 lb
$47.99A plain 50 lb bag of pelletized dolomitic lime for raising the pH of acidic soil through a standard spreader; apply at the rate your soil test calls for.
Best for: correcting acidic soil on a budget
Check price on Amazon
Jonathan Green Mag-I-Cal Soil Food for Acidic Soil, 15,000 sq ft
$61.20Soluble calcium carbonate with humates that Jonathan Green says has the pH-raising power of up to 15 bags of limestone, in a 54 lb bag covering 15,000 sq ft.
Best for: faster pH correction than ground limestone
Check price on Amazon
MySoil Soil Test Kit
$34.26A prepaid mail-in lab test that reports pH and 13 plant-available nutrients in 6 to 8 days with product and rate recommendations, far more precise than color capsules.
Best for: testing before liming or fertilizing
Check price on Amazon
Luster Leaf Rapitest Soil Test Kit, 40 Tests
$18.68An inexpensive capsule-and-color-chart kit with 10 tests each for pH, nitrogen, phosphorus and potash, useful for quick spot checks around the yard.
Best for: cheap at-home pH checks
Check price on Amazon
Scotts Turf Builder EdgeGuard DLX Broadcast Spreader
$94.97A pre-calibrated push broadcast spreader holding up to 15,000 sq ft of product, with an EdgeGuard shield that keeps granules off beds and driveways.
Best for: lawns up to about a third of an acre
Check price on Amazon
EarthWay 2150 Commercial 50 lb Broadcast Spreader
$279.99A commercial push spreader with 13 inch pneumatic tires, a slide-out grate, fully enclosed gearbox and a 3-hole drop with side-spread control for feathered edges.
Best for: rough or bumpy lawns
Check price on Amazon
Lesco 50 lb Commercial Push Spreader
$445.00The long-running landscaper standard with an enclosed gearbox and powder-coated carbon steel frame, and settings printed on many pro fertilizer bags.
Best for: pros and serious DIYers who spread weekly
Check price on Amazon
Agri-Fab 130 lb Tow-Behind Broadcast Spreader
$249.99A universal-hitch tow spreader with a 10 to 12 ft spread width, enclosed gears and a hopper rated to cover up to half an acre per fill.
Best for: half-acre to acre lawns with a riding mower
Check price on Amazon
Brinly PA-42BH-A 42 in Tow-Behind Plug Aerator
$379.00Heat-treated 16-gauge spoons remove plugs up to 3 inches deep across three independently rotating sections that limit turf tearing on turns, with a 175 lb weight tray and folding tow bar.
Best for: aerating uneven yards with a rider or ZTR
Check price on Amazon
Yard Butler ID-6C Manual Lawn Coring Aerator
$48.95A long-handled powder-coated steel step aerator that pulls two cores per push, the right tool for compacted paths and small patches.
Best for: spot-aerating small, compacted areas
Check price on AmazonOn this page
How much lime do I need per 1,000 square feet?
| Starting pH | Sandy soil | Loam | Clay |
|---|---|---|---|
| pH 6.0 to 6.5 | 20 lb | 35 lb | 50 lb |
| pH 5.5 to 6.5 | 40 lb | 70 lb | 100 lb |
| pH 5.0 to 6.5 | 60 lb | 105 lb | 150 lb |
| pH 4.5 to 6.5 | 80 lb | 140 lb | 200 lb |
What soil pH does each grass type prefer?
| Grass | Preferred pH |
|---|---|
| Kentucky bluegrass | 6.0 to 7.0 |
| Tall fescue | 5.5 to 7.0 |
| Perennial ryegrass | 6.0 to 7.0 |
| Fine fescue | 5.5 to 6.5 |
| Bermudagrass | 6.0 to 7.0 |
| Zoysiagrass | 6.0 to 7.0 |
| St. Augustinegrass | 6.0 to 7.5 |
| Bahiagrass | 5.5 to 6.5 |
| Centipedegrass | 5.0 to 6.0 (do not lime above 6.0) |
How is the lime rate calculated?
The calculator uses pounds per 1,000 sq ft = (target pH minus current pH) x 10 x a texture factor of about 4 pounds per tenth of a pH unit for sandy soil, 7 for loam and 10 for clay, then scales to your area and bag size. It caps each application at 50 pounds per 1,000 square feet and tells you how many applications to split the total into. The texture factors reflect common extension tables that list roughly 40, 70 and 100 pounds per 1,000 square feet to raise sandy, loam and clay soils by one full unit.
These are estimates because soils with the same pH can need very different amounts of lime. The buffer pH on a lab soil report measures that reserve acidity directly, which is why a lab test is worth its cost before liming a whole lawn. Home capsule kits such as the Luster Leaf Rapitest Soil Test Kit, 40 Tests are fine for a quick check of pH but cannot give a lime rate. See how to test soil pH.
What is the difference between pelletized, dolomitic and calcitic lime?
Pelletized lime is finely ground limestone bound into pellets so it spreads cleanly through a broadcast spreader with less dust; applied at the same weight, it corrects pH like the ground limestone it is made from. Dolomitic lime, such as the Old Castle Pro Pelleted Dolomitic Limestone, 50 lb, contains magnesium as well as calcium and suits soils that test low in magnesium. Calcitic lime is mostly calcium carbonate and is the better choice when magnesium is already high. Soluble calcium products like the Jonathan Green Mag-I-Cal Soil Food for Acidic Soil, 15,000 sq ft are applied at much lower rates listed on their own label, so do not use the table above for them. Gypsum, such as the The Andersons NutraSoft OP Pelletized Gypsum, 40 lb, adds calcium but does not raise pH.
When is the best time to apply lime to a lawn?
Lime can go down any time the ground is not frozen, but fall and early spring are the most practical. Fall applications have winter freeze and thaw to help work lime into the soil, and the pH change, which takes months, is underway by the growing season. Lime works slowly, so do not retest for several months after applying. Spread it with a broadcast spreader in two perpendicular passes; the Scotts Turf Builder EdgeGuard DLX Broadcast Spreader or the EarthWay 2150 Commercial 50 lb Broadcast Spreader handle pelletized lime, while some spreaders are not rated for it, so check the manual. Core aeration before liming helps it reach the root zone faster.
Frequently asked questions
How much lime do I need for 5,000 square feet?
To raise a loam soil from pH 5.5 to 6.5, plan roughly 70 pounds per 1,000 square feet, or about 350 pounds for 5,000 square feet, which is seven 50 pound bags. Because that exceeds about 50 pounds per 1,000 square feet, split it into two applications several months apart. Sandy soil needs about 200 pounds total and clay about 500, based on a soil test.
Can you put too much lime on a lawn?
Yes. Overliming pushes pH above the range grass prefers, which ties up iron, manganese and phosphorus and can yellow the lawn. High pH is much slower and harder to lower than low pH is to raise. That is why lime should be based on a soil test, applied at no more than about 50 pounds per 1,000 square feet at a time, and retested before adding more.
How long does lime take to change soil pH?
Lime reacts slowly. Most of the change happens over several months to a year, and finely ground or pelletized limestone reacts faster than coarse material. Watering after application and core aerating beforehand help. Wait at least several months, ideally a year, before retesting soil and deciding whether another application is needed.
Should I use pelletized or powdered lime?
Pelletized lime is the practical choice for homeowners because it spreads evenly through a standard broadcast spreader with far less dust. It is made from finely ground limestone, so at the same weight it corrects pH similarly. Powdered agricultural lime can cost less per pound for large areas but is dusty and hard to spread evenly without specialized equipment.
Does my lawn need lime?
Only if a soil test shows acidic soil below the range your grass prefers, usually below about pH 6.0 for most lawn grasses. Moss and poor fertilizer response can hint at acidity but have other causes too. Many lawns in dry western regions are already alkaline and should never be limed. Test first with a lab kit or through your local extension office.
Researched, not professional advice. This page is compiled from published specifications, manuals, labels and owner-review consensus, not hands-on testing. Follow the manufacturer's instructions and product label, and consult a qualified professional where safety, chemicals, fuel or structures are involved. As an Amazon Associate we earn from qualifying purchases.