Project Cost HQ is a collection of free calculators for hobbyists and planners. Homebrewing, reloading economics, 3D-printing costs, power tools, and wedding budgets — no signup, no fees.
Every tool on this site produces planning estimates, not professional advice. Prices vary by region and change over time; ratings and capacities come from manufacturers and public sources. Always verify critical numbers — vehicle ratings, electrical loads, structural spans, tax incentives — against the official source or a licensed professional before acting on them.
Every calculator here runs on your inputs and published reference data, with the method shown on the page. The homebrew tools use the standard formulas published across homebrewing references — ABV from original and final gravity, priming sugar by target carbonation volumes, strike-water temperature from grain bill and ratio. The power-tool comparisons use manufacturer-published specifications, labeled as claims rather than test results. Wedding figures come from The Knot 2026 Real Weddings Study, and reloading economics use 2026 U.S. retail component averages with the math exposed line by line. Wherever a number is an average rather than a measurement, the page says so, and wherever you have a real price — a filament spool, a primer brick, a venue quote — you can enter it and replace the default. All math runs in your browser; nothing you type is stored or sent anywhere.
Specification data is checked against manufacturer documents, survey figures are refreshed when new study data publishes, and retail averages are reviewed on a regular cycle and carry their year on the page. Formulas change rarely, but prices do not sit still — a component average from a prior year is labeled as such rather than quietly reused. If a spec on this site disagrees with a manufacturer's current sheet, the sheet wins and the contact below reaches a person who will fix it.
These are planning tools for hobbies, with hobby-grade stakes — mostly. A cost-per-round figure is economics, not loading advice: this site publishes cost math only, never load data, and reloading itself demands published manufacturer data and established safety practice. An ABV estimate is only as good as your hydrometer readings. A wedding average describes thousands of other couples' weddings, not yours. Use the numbers to plan and to compare, and verify anything safety-related against the primary source.