Lime Calculator

Estimate how much garden lime may be needed to raise acidic soil pH. Calculate lime pounds, ounces, bags needed, application rate, cost, split applications, and lime amount for gardens, raised beds, lawns, flower beds, and planting areas.

Calculate Lime Needed

Lime Needed = Area × pH Change × Soil Texture Factor × Mixing Depth Factor ÷ Lime Strength.
Your result will appear here.

How the lime calculator works

pH change mode:
The calculator estimates lime from current pH, target pH, garden area, soil texture, mixing depth, and lime strength.

Known rate mode:
The calculator uses a lime application rate such as pounds per 100 square feet or pounds per 1,000 square feet.

Bag coverage mode:
The calculator estimates bags needed using the coverage listed on the lime bag.

Cost mode:
The calculator estimates lime pounds, bags to buy, purchase cost, and split application amount.

Why use a lime calculator?

A lime calculator helps estimate how much lime to buy and apply before adjusting acidic soil.

It can help plan garden lime applications, compare bag coverage, estimate costs, calculate pounds per area, and avoid over-applying lime too quickly.

What your result means

Your result shows estimated lime needed, lime ounces, bags needed, application rate, amount per split application, total cost, area, pH change, lime type, and lime strength adjustment.

Lime calculator formulas

Frequently asked questions

How do I calculate how much lime I need?

Use a soil test when possible. For a rough estimate, calculate the pH change needed, adjust for soil texture and area, then divide by lime strength.

What does lime do to soil?

Lime raises acidic soil pH and can add calcium. Dolomitic lime also adds magnesium.

Can I apply too much lime?

Yes. Too much lime can raise soil pH too high and make some nutrients less available. Retest soil before adding more.

How long does lime take to work?

Lime works gradually. Soil pH changes may take weeks to months depending on product type, soil moisture, soil texture, and how well the lime is incorporated.

Is this lime calculator exact?

No. This is an estimate. Actual lime needs depend on lab soil test recommendations, buffering capacity, soil texture, organic matter, lime quality, mixing depth, and local growing conditions.