Landscaping, deck, and outdoor

Outdoor projects have one variable indoor projects do not: weather

Every outdoor calculator accounts for material exposure to rain, freeze-thaw, UV, and soil moisture. Fence posts in contact with soil rot from the bottom up within 5 to 8 years if not pressure-treated. Mulch decomposes about an inch per year, requiring annual top-ups. Gravel compacts 15 to 20 percent when you run a plate compactor over it, so you need to order more loose volume than the finished depth suggests. These environmental factors are built into the waste percentages and overage recommendations on every tool.

Hardscape: deck, fence, and patio

These three projects share a common foundation: concrete footings. Every deck post, fence post, and patio edge restraint sits on or in concrete that extends below the frost line. The depth of that frost line varies from 18 inches in the South to 48 inches in northern Minnesota. This single variable changes the concrete quantity by 2 to 3 times for the same project.

The deck calculator estimates decking boards, joists, beams, posts, and concrete footings from your deck dimensions and material choice. The fence calculator does the same for posts, rails, pickets, and concrete by linear footage. The paver calculator handles paver count, gravel base, bedding sand, polymeric joint sand, and edge restraint. All three have project planners that chain multiple calculations into a single material list: deck planner, fence planner, and patio planner.

For cost breakdowns including DIY vs professional labor, regional pricing, and hidden costs, see the dedicated cost guides: cost to build a deck, cost to build a fence.

Softscape: mulch, topsoil, sod, and gravel

These four materials all use the same volume formula: area in square feet times depth in inches divided by 324 equals cubic yards. The number 324 is just 27 cubic feet per yard times 12 inches per foot. Despite sharing a formula, the four materials differ in density, cost, and how they are sold.

The mulch calculator outputs cubic yards (how landscape supply yards quote bulk mulch) and bag count (how big-box stores sell it). The crossover point is about 2 cubic yards: below that, bags are practical; above that, bulk delivery saves money and hours of hauling. The gravel calculator outputs both cubic yards and tons, because gravel suppliers quote by weight while mulch suppliers quote by volume. One cubic yard of crushed stone weighs about 1.4 tons — confusing the two units results in ordering 30 percent too much or too little.

The topsoil calculator handles soil volume for garden beds and lawn prep, with guidance on screened vs amended vs fill-grade soil. The sod calculator estimates pallets, rolls, or individual slabs by lawn area, with a 5 percent waste buffer for cuts at curves and edges.

For projects that combine multiple materials (a patio with a gravel base, surrounded by new sod, with mulch in the garden beds), order everything from one landscape supply yard on the same delivery. Most yards split-load two or three materials on one truck, saving $100 or more in delivery fees.

Water: pool maintenance and rainwater collection

The pool chlorine calculator doses chemicals based on pool volume in gallons. Most pool owners estimate their volume incorrectly, which means every chemical dose is wrong — too much chlorine bleaches swimsuits and burns eyes, too little lets algae bloom. The calculator computes volume from your pool dimensions and gives exact doses for liquid bleach, tablets, and shock treatment.

The rainwater calculator sizes collection tanks from roof area and local rainfall. A 1,500 square foot roof in an area that gets 30 inches of annual rainfall collects roughly 28,000 gallons per year — enough to irrigate a large garden for the entire growing season without using municipal water.

Buying guides

For deck material selection, read the deck materials buying guide with 20-year total cost of ownership analysis comparing composite, pressure-treated pine, and cedar.