Tons of Lime Per Acre: Rates & How to Calculate

This calculator works out how many tons of lime (agricultural limestone) you need to apply to a lawn or field. You enter the area length and width, plus the desired depth of the lime layer, and it returns the volume in cubic yards and cubic feet — from there you can convert to tons using the density of the lime you plan to spread. The first result shown is the volume in cubic yards, which is the most common unit for ordering bulk lime.

Formula

The calculator uses the standard volume formulas for a rectangular area:

• Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
• Cubic yards = length (ft) × width (ft) × depth (in) ÷ 324

Where:

• length (l) = lawn length in feet
• width (w) = lawn width in feet
• depth (d) = desired lime depth in inches

The divisor 324 comes from converting: 1 cubic yard = 27 cubic feet, and 1 foot = 12 inches. So (l × w × d/12) / 27 = l × w × d / 324.

Worked Example

Using the default values (length = 40 ft, width = 25 ft, depth = 3 in):

1. Cubic feet = 40 × 25 × 3 ÷ 12 = 1000 ÷ 12 = 250 ft³
2. Cubic yards = 40 × 25 × 3 ÷ 324 = 3000 ÷ 324 = 9.26 yd³

The calculator shows 9.26 cubic yards and 250 cubic feet. To convert to tons, multiply the cubic yards by the density of the lime (typically 1.2–1.7 tons per cubic yard, depending on moisture and particle size). For dry agricultural lime, a common estimate is 1.4 tons per cubic yard, so 9.26 × 1.4 ≈ 13 tons. But the actual tons per acre depends on the soil test recommendation, not just the volume.

Why Soil Tests Matter

Lime is applied to raise soil pH. The amount needed is not a fixed number — it depends on your soil’s current pH, the target pH (usually 6.5–7.0 for lawns), and the soil’s buffering capacity (how resistant it is to pH change). A soil test from a lab will give a specific recommendation in pounds of lime per 1,000 square feet or tons per acre. For example, a sandy soil with pH 6.0 might need 1 ton per acre, while a clay soil with pH 5.0 might need 3 tons per acre. Always follow the soil test, not a generic rule.

How to Choose the Right Lime

Not all lime is the same. The two main types are:

• Calcitic lime (calcium carbonate) — raises pH and adds calcium.
• Dolomitic lime (calcium magnesium carbonate) — raises pH and adds both calcium and magnesium. Use this if your soil test shows low magnesium.

Also check the Effective Neutralizing Value (ENV) or Calcium Carbonate Equivalent (CCE) on the label. This tells you how much the lime will actually neutralize compared to pure calcium carbonate. If your lime has a CCE of 80%, you’ll need to apply 1/0.8 = 1.25 times more than the soil test recommends.

Common Mistakes

• Mixing up tons and pounds — soil test recommendations are often given in pounds per 1,000 sq ft, but bulk orders are in tons per acre. 1 ton = 2,000 pounds; 1 acre = 43,560 sq ft.
• Applying too much at once — more than 2–3 tons per acre can harm turf. If the recommendation is higher, split it into two applications 6–12 months apart.
• Ignoring particle size — finer lime reacts faster. Pelletized lime is easier to spread but often has a lower CCE per pound because of the binder.
• Applying without a soil test — raising pH too high (above 7.5) can lock up nutrients like iron and manganese.

Cost and Application Tips

Bulk agricultural lime is usually cheaper per ton than bagged or pelletized lime, but you need a spreader that can handle the volume. For a typical 5,000 sq ft lawn needing 1 ton per acre, that’s about 115 pounds of lime (since 1 acre = 43,560 sq ft, 1 ton per acre = 2,000 lbs / 43,560 sq ft ≈ 0.046 lbs/sq ft, × 5,000 = 230 lbs). Wait — check: 2,000 / 43,560 = 0.0459 lbs/sq ft. × 5,000 = 229.5 lbs. So about 230 lbs. That’s roughly 5 bags of 50-lb lime. Always apply lime evenly, and water it in lightly to help it react.

Alternatives to Lime

If your soil is alkaline (pH too high), you need the opposite — sulfur or aluminum sulfate to lower pH. If your soil test shows adequate calcium and magnesium but low pH, you might consider wood ash (raises pH and adds potassium) but it’s less predictable. For small areas, some gardeners use ground oyster shells, which are slow-acting. But for most lawns, standard agricultural lime is the safest, most cost-effective choice.

Frequently Asked Questions

How many tons of lime per acre for a lawn?

There’s no single answer — it depends on soil pH and soil type. A typical recommendation ranges from 1 to 3 tons per acre, but a soil test is essential. For example, a loam soil with pH 5.5 might need about 2 tons per acre to reach 6.5.

Can I apply lime and fertilizer at the same time?

Yes, but avoid mixing them in the spreader because lime dust can react with ammonium-based fertilizers and release ammonia gas. Apply them separately, a few days apart, or use a drop spreader for one and a rotary spreader for the other.

How long does lime take to work?

Lime reacts slowly — it can take 3–6 months to see a noticeable pH change, and full effect may take a year or more. That’s why it’s best to apply lime in the fall or early spring, well before planting.

What happens if I apply too much lime?

Over-liming raises pH too high, making nutrients like iron, manganese, and phosphorus less available. Symptoms include yellowing leaves and poor growth. It’s difficult to reverse, so always follow soil test recommendations.

Is pelletized lime better than powder?

Pelletized lime is easier to spread and less dusty, but it’s often more expensive per ton of actual neutralizing material. Powdered lime reacts faster but is messier. Both work if applied at the correct rate based on CCE.

How do I convert tons per acre to pounds per 1,000 sq ft?

Multiply tons per acre by 45.9. For example, 2 tons per acre × 45.9 = 91.8 lbs per 1,000 sq ft. That’s because 1 acre = 43,560 sq ft, and 2,000 lbs ÷ 43.56 = 45.9.

Related

• Lime per Acre: How Much to Apply
• Ag Lime Application Rates per Acre
• Triangular Plant Spacing Calculator (Offset Rows)

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