Lime per Acre: How Much to Apply

To directly answer the question: most lawns and gardens need between 1 and 2 tons (2,000–4,000 lbs) of agricultural lime per acre per application. The exact amount depends on your soil’s current pH and target pH, which only a soil test can tell you accurately.

Formula

The calculator above works out the volume of soil in a given area and depth, which is the first step in figuring out how much lime you need. The formula is:

Volume (yd³) = (Length × Width × Depth in inches) / 324

Where:

• Length = lawn length in feet
• Width = lawn width in feet
• Depth = soil depth in inches (usually 6–8 inches for lime incorporation)
• 324 = conversion factor (1 cubic yard = 27 cubic feet; 1 foot = 12 inches, so 27 × 12 = 324)

This volume tells you how many cubic yards of soil you are treating. Lime application rates are typically given in pounds per 1,000 square feet or tons per acre, so you’ll also need to know your area in square feet (Length × Width).

Worked Example

Using the default values from the calculator above: a lawn that is 40 ft long, 25 ft wide, and you want to know the soil volume to a depth of 3 inches.

1. Calculate area: 40 ft × 25 ft = 1,000 ft².
2. Convert depth to feet: 3 in ÷ 12 = 0.25 ft.
3. Volume in cubic feet: 1,000 ft² × 0.25 ft = 250 ft³.
4. Convert to cubic yards: 250 ft³ ÷ 27 = 9.26 yd³.

The calculator gives 9.26 yd³ (rounded to 2 decimals) and 250 ft³. This volume is not the amount of lime—it’s the soil volume you’re amending. Lime is usually applied by weight, not volume.

Why Soil pH Matters

Lime (calcium carbonate or similar) raises soil pH, making it less acidic. Most turfgrasses and garden vegetables prefer a pH between 6.0 and 7.0. When soil pH drops below 6.0, nutrients like phosphorus, potassium, and nitrogen become less available to plants, and beneficial microbial activity slows. Applying lime without a soil test is like guessing how much salt to add to a soup you haven’t tasted—you might make it worse.

Soil pH is measured on a scale of 0 to 14, with 7 being neutral. Most natural soils in humid regions are acidic (pH 5.0–6.5) because rainfall leaches calcium and magnesium. In arid regions, soils are often alkaline (pH 7.5–8.5) and need sulfur, not lime. Always test before adding lime.

How to Determine Your Lime Rate

The standard recommendation from agricultural extension services is based on a soil test that reports your current pH and your soil’s buffer pH (a measure of how resistant it is to pH change). A common guideline is:

• If pH is 6.0–6.5: apply 1 ton per acre (about 50 lbs per 1,000 ft²) to maintain.
• If pH is 5.5–6.0: apply 1.5–2 tons per acre (about 70–90 lbs per 1,000 ft²).
• If pH is 5.0–5.5: apply 2–3 tons per acre (about 90–140 lbs per 1,000 ft²).
• If pH is below 5.0: apply 3–4 tons per acre, but split into two applications a few months apart to avoid shocking the soil.

These are rough averages; your soil’s texture (sand, silt, clay) and organic matter content affect how much lime is needed. Clay soils require more lime than sandy soils to change pH by the same amount. A soil test lab will give you a precise recommendation in pounds per 1,000 square feet or tons per acre.

Types of Lime and Application Tips

Not all lime is the same. Agricultural lime (calcitic) is calcium carbonate. Dolomitic lime contains magnesium as well, which is helpful if your soil test shows low magnesium. Pelletized lime is easier to spread but is usually more expensive per ton. Hydrated lime (calcium hydroxide) acts faster but is more caustic and can burn plants if overapplied—use only if a soil test specifically calls for it.

Application tips:

• Apply lime in fall or early spring so it has time to react before the growing season.
• Incorporate lime into the top 6 inches of soil if possible; for established lawns, top-dressing with a drop spreader works but takes longer to affect pH.
• Water lightly after applying to help lime move into the soil.
• Do not apply lime and nitrogen fertilizer at the same time; the ammonia in fertilizer can be lost as gas when pH is high.

Common Mistakes and Misconceptions

One of the biggest mistakes is applying lime

Related

• Lawn Fertilizer Calculator: Pounds of Product from Nitrogen
• Vegetable Garden Row Calculator: Rows and Plants
• Ag Lime Application Rates per Acre

in l | Lawn length | ft | 40 | 0 | 100000
in w | Lawn width | ft | 25 | 0 | 100000
in d | Depth | in | 3 | 0 | 120
out yd | Volume | yd³ | l * w * d / 324 | 2
out ft3 | Volume | ft³ | l * w * d / 12 | 1