Calculators • Project Math • Planning Tools

DIY Calculators

Use simple DIY calculators to estimate materials, battery runtime, power needs, sizing, and project numbers before you buy parts or start work.

Available Calculators

Start with the calculator that matches what you need to estimate. The list below updates automatically when published calculator pages are marked for the directory.

Materials & Measurements

Gravel Calculator

Estimate how much gravel you need in cubic yards, tons, and bags based on project size, depth, gravel type, and waste buffer.

Concrete Bag Calculator

Estimate how many bags of concrete you need for slabs, pads, footings, post holes, and small projects based on size, bag yield, and waste buffer.

Mulch Calculator

Estimate how much mulch you need in cubic yards, cubic feet, and bags based on area size, mulch depth, bag size, and waste buffer.

Raised Bed Soil Calculator

Estimate how much soil you need for a raised garden bed in cubic feet, cubic yards, bags, and simple soil mix amounts.

Paint Calculator

Estimate how much paint you need in gallons and quarts based on room size, wall area, coats, coverage rate, and waste buffer.

Fence Post Spacing Calculator

Estimate how many fence posts you need and the spacing between posts based on fence length, layout type, gate openings, and maximum spacing.

Power & Wiring Basics

Watts to Amps Calculator

Convert watts to amps for DC, single-phase AC, and three-phase AC power using voltage, power factor, and a planning buffer.

Power Supply Calculator

Estimate what size DC power supply you may need based on voltage, load current, number of devices, startup surge, and planning buffer.

Voltage Drop Calculator

Estimate voltage drop, voltage at the load, and power loss based on wire size, wire length, amps, voltage, wire material, and circuit type.

DC Wire Gauge Calculator

Estimate wire gauge for 12V, 24V, and 48V DC projects based on amps, one-way wire length, wire material, and target voltage drop.