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Calcimator

Soil Amendment Calculator

Calculate how much lime, sulfur, compost, and fertilizer your garden soil needs.

Inputs

sq ft
%

Results

Lime Needed

5 lbs

≈ 20 sticks of butter

Sulfur Needed0 lbs
Compost Needed3 cu ft
Fertilizer (10-10-10)2 lbs
Estimated Cost$17.50
How to Use This Calculator
  1. Enter your garden area in square feet and run a soil test to obtain your current soil pH and organic matter percentage.
  2. Enter your current pH and target pH — most vegetables prefer 6.0–7.0; blueberries prefer 4.5–5.5.
  3. Select your soil type (sandy, loam, or clay) since clay soils require more amendment material to shift pH.
  4. Review Lime Needed (lbs) to raise pH or Sulfur Needed (lbs) to lower pH, and apply the recommended amount evenly.
  5. Use the Compost Needed (cu ft) and Fertilizer (10-10-10) outputs to improve organic matter and baseline fertility.

How the result changes with Target Soil pH

Target Soil pHLime Needed
4.40 lbs
5.40 lbs
6.65.5 lbs
7.610.5 lbs

What each input means

Garden Area
Total garden area to amend.
Current Soil pH
Current soil pH from a soil test.
Target Soil pH
Desired soil pH. Most vegetables prefer 6.0-7.0.
Organic Matter %
Current organic matter percentage from soil test. Ideal is 5%+.
Soil Type
1=Sandy, 2=Loam, 3=Clay. Clay requires more amendment.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Garden Area = 100, Current Soil pH = 5.5, Target Soil pH = 6.5, Organic Matter % = 2 = 5 input(s) provided
  2. Calculate Lime Needed
    Lime Needed
    5 = 5
  3. Calculate Sulfur Needed
    Sulfur Needed
    0 = 0
  4. Calculate Compost Needed
    Compost Needed
    3 = 3

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