Available Water Capacity Calculator
Calculate available water capacity from field capacity, wilting point, root depth, and bulk density. Plan irrigation amounts and frequency.
Free Soil Calculators
16 toolsSoil health, testing, and amendment tools. Browse our free soil tools below — no sign-up required.
Cation Exchange Capacity (CEC) Calculator
Calculate and interpret cation exchange capacity from soil test data. Understand nutrient holding capacity and base saturation ratios.
Compost Application Rate Calculator
Calculate compost application rate in tons per acre based on target nitrogen availability, total N content, and mineralization rate.
Field Capacity Estimator
Estimate soil field capacity from texture and organic matter using Saxton-Rawls pedotransfer functions. Plan irrigation scheduling.
Gypsum Application Rate Calculator
Calculate gypsum tons per acre to reduce sodium percentage in soil based on soil Na%, target Na%, CEC, and treatment depth.
Lime Application Rate Calculator
Calculate agricultural lime application rate in tons per acre using buffer pH, lime factor, and effective neutralizing power (ENP).
Organic Matter & Nitrogen Mineralization Calculator
Estimate nitrogen mineralization from soil organic matter percentage. Calculate how much N your soil organic matter contributes annually.
Permanent Wilting Point Estimator
Estimate soil permanent wilting point from texture and organic matter using Saxton-Rawls pedotransfer functions for irrigation planning.
Soil Bulk Density Calculator
Calculate soil bulk density from core sample measurements. Determine dry mass per volume for compaction assessment and soil health.
Soil Carbon Sequestration Calculator
Estimate carbon stored in soil from organic matter change. Calculate CO₂ equivalent sequestered per acre from soil health practices.
Soil Compaction Assessment Calculator
Assess soil compaction severity from penetrometer readings. Estimate yield drag percentage and get management recommendations.
Soil Erosion (USLE) Calculator
Estimate annual soil loss using the Universal Soil Loss Equation (USLE). Enter R, K, LS, C, and P factors for erosion prediction.
Soil Moisture Content Calculator
Calculate gravimetric and volumetric soil moisture content from wet and oven-dry soil sample weights. Essential for irrigation management.
Soil pH Adjustment Calculator
Calculate the amount of lime or sulfur needed to adjust soil pH based on current pH, target pH, soil texture, and buffer index.
Soil Test Interpretation Calculator
Interpret soil test results for pH, phosphorus, potassium, organic matter, and CEC. Classify nutrient levels and get recommendations.
Soil Texture Triangle Calculator
Determine USDA soil texture class from sand, silt, and clay percentages. Enter particle size analysis results to classify your soil.