Reference

Sometimes you do not need a calculator. You need to know how far a yard of mulch goes at three inches, what a yard of gravel weighs, or what a supplier means by "crusher run". These pages hold the figures and definitions that the rest of the site is built on.

• Coverage rates

  How far a cubic yard, a bag or a ton goes at each depth, plus pavers, sod, seed, plants and deck boards.

• Unit conversions

  Length, area, volume, weight, density, application rates and slope, in both directions.

• Material weights and densities

  Pounds per cubic yard for mulch, soil, stone and concrete, with bag, pallet and lumber weights.

• Glossary

  Over 70 terms used by suppliers and installers, explained in plain English.

• Measurement worksheet

  A printable page for recording each area before you calculate or order.

Where the numbers come from

Coverage figures are geometry. A cubic yard is 27 cubic feet, and spread one inch deep it covers 324 square feet, whatever it is made of. Those tables will never change.

Weights and densities are different. They are typical values for common materials, and real products vary with moisture, source and grading. We give ranges where the variation is large, and say which single value each calculator uses. Where your supplier quotes a figure of their own, theirs is the better one to use.

Seeding and fertilizer rates are typical of what seed labels and university extension services recommend. They are a guide for estimating how much to buy. The label on the product in your hand has the final word.

All reference pages carry the date they were last reviewed. How we choose, check and update these values is described in the methodology, and corrections are logged in the editorial policy.