Methodology

This page explains how a calculator on this site actually gets made and kept accurate: the real algorithm behind each result, where the data comes from, and who does each step.

How we calculate your result

Every calculator on this site uses a named, checkable formula, never a black box. Here is the actual math behind each family of tools:

• Acres per hour (home, mowing, bush hog, farm equipment): width in feet × speed in mph × field efficiency ÷ 8.25. The constant 8.25 is 43,560 square feet per acre divided by 5,280 feet per mile.
• Sprayer gallons per acre: 5,940 × nozzle GPM ÷ (mph × nozzle spacing in inches). The constant 5,940 is 43,560 × 12 ÷ 88.
• Seeding rate: target plant population ÷ (germination % × field survival %) gives seeds to plant; divide that by seeds per pound and by purity % to get pounds of seed per acre.
• Plant population: plants counted × 43,560 ÷ (row length × row spacing) from a stand count, or 6,272,640 ÷ (row spacing × seed spacing in inches) from a planter setting.
• Acreage and area shapes: length × width for a rectangle, ½ × base × height for a triangle, Heron’s formula for a triangle from three sides, π × radius² for a circle, and the shoelace formula for an irregular shape from corner coordinates.
• Cost calculators (bush hog cost, land clearing cost) work differently: hours needed come from the acres-per-hour formula above, and dollar figures are either your own fuel, labor and wear inputs multiplied by those hours, or a planning range compiled from published cost guides multiplied by your acreage. These are ranges for budgeting, not a measured formula, and every page says so.

Every calculator page shows its own formula inline and derives its constants, so you can check any result by hand without taking our word for it.

Where the process starts: research

Where a number is not a fixed constant, such as a seeding rate or a cost range, Jordan researches it from official and primary sources: university and cooperative extension publications, government agencies, and manufacturer documentation. Where recommendations vary by region, the page says so and points to local guidance instead of pretending one number fits everywhere.

Then it gets written

Chris writes the page around that research: the formula, a plain explanation, worked examples, and the common questions people actually ask.

Then it gets tested

Eric checks the finished calculator against hand-worked examples, including edge cases such as blank, zero or invalid input, before it goes live. See our quality standards for the full testing process.

Then it gets reviewed

Michael Steve reviews the data, the formula and the page itself before anything is published or changed.

And kept current afterward

Madelynne follows up on reader-reported errors and keeps reference data current. See our corrections process.

This process is the same one described at a higher level in our editorial policy.