Free Soil Tools and Calculators

Some of these tools read USDA’s soil survey for the point you pick; the others work through a measurement or a calculation you do yourself, using an extension method. Every result shows where its numbers come from.

Check the soil at an address

Type an address or ZIP code, or tap the map, and the checker reads USDA’s ratings and properties for the main soil of the map unit there. USDA’s soil survey (SSURGO) is mapped at scales from 1:12,000 to 1:63,360 for planning by landowners and counties, and a map unit holds one to three major soils^[1], so treat a result as what to expect on the lot, then check the lot itself.

• Expansive Soil CheckerSee how much the soil at an address shrinks and swells, and whether USDA says it can damage buildings.
• Water Table DepthFind how close to the surface the seasonal water table comes at an address.
• Prime Farmland CheckerCheck USDA's farmland classification for the soil at any US address.
• Building Site CheckerSee USDA's soil ratings for houses with and without basements at an address.
• Septic Suitability CheckerSee USDA's rating for a septic drain field at any US address.

Find your soil’s texture

Texture, the mix of sand, silt and clay, sets how a soil drains, holds water and works. Measure it in a jar of water, judge it by feel with a ribbon test, or enter lab percentages on the texture triangle; each test ends in a USDA texture class^[2].

• Soil Texture Triangle CalculatorEnter sand, silt and clay to name your USDA texture class on the triangle.
• Soil Jar Test CalculatorSettle your soil in a jar, measure the layers, and get your USDA texture class.
• Soil Ribbon TestAnswer a few questions about how your soil feels to estimate its texture class.

Work out how much to buy

The amount calculators turn an area and a depth into cubic feet, cubic yards and bags. Their depths come from extension guidance: 4 to 6 inches of settled topsoil for a new lawn^[3], 3 to 4 inches of compost worked into a new garden^[4], and raised beds at least 6 to 12 inches deep^[5].

• Topsoil CalculatorEnter area and depth for topsoil in cubic yards, bags and estimated weight.
• Raised Bed Soil CalculatorEnter bed size and depth for the soil you need, split into your own mix.
• Compost CalculatorArea and depth to cubic yards and bags, using university application rates.

Measure your soil’s physical properties

These calculators work from a sample you take or a test you run: a ring of soil weighed wet and dry gives bulk density, and from it pore space; wet and dry weights give moisture; a ring of water timed as it soaks in gives an infiltration rate^[6][7]. Each can also start from USDA’s mapped values for your address.

• Soil Bulk Density CalculatorWork out soil bulk density from a ring sample, and whether it restricts roots.
• Soil Porosity CalculatorTurn bulk density into pore space, and see how it compares with the ideal.
• Soil Moisture Content CalculatorFind soil moisture from wet and dry weights, gravimetric and volumetric.
• Soil Water Holding Capacity CalculatorHow much plant-available water your root zone holds, in inches and gallons.
• Soil Infiltration Rate CalculatorTime how fast an inch of water soaks in, for a rate in inches per hour.
• Lime and Sulfur CalculatorWork out how much lime raises, or sulfur lowers, your soil’s pH, by area and texture.

Which tool answers your question

How the tools work

Nothing calculates until you press the button, and a result changes only when you ask again. Where USDA publishes no value for a soil, the tool says so instead of filling the gap with an estimate. The address tools show the soil series and map unit they read, so you can look the same soil up in Web Soil Survey, NRCS’s own application for the survey^[8]. For the whole country at once, see the soil maps; for the background, the learn section.