About GarageDoorCalcs
GarageDoorCalcs is an independent project with one goal: to gather the everyday calculations homeowners, landlords and buyers reach for around a garage door — doors & installation, openers & motors, springs & hardware, repair & maintenance, insulation & energy, and sizing & measurement — in one focused, free, no-signup hub with transparent formulas, so you can budget a project and sanity-check a garage-door company’s quote.
Who is behind it
Author and curator
To be clear about credentials: I am the author and curator of this site — not a licensed garage-door installer, an IDEA-accredited door systems technician or a manufacturer engineer, and I claim no trade credential. What I bring is relevant and real: building deterministic online calculators (open-source Python projects) and electronic-engineering training, i.e. rigor on the arithmetic and sizing math. That is what it takes to curate a hub of calculators: transparent method, correct formulas, cited conventions and worked examples.
Our principle: transparent & durably correct
Every calculator shows its formula, a worked example and a reference table. The tools rest only on timeless garage-door math (project cost = door price + labor (hours × your $/hr) + Σ add-ons − trade-in, ×(1 + contingency); cost by size = width_ft × height_ft × your $/sq ft + install; spring life = rated cycles ÷ (cycles per day × 365); door weight = area × labeled lb/sq ft; opener HP by door-weight band; insulation payback = added cost ÷ annual $ saved; rough opening = door size + labeled clearances) and stable conventions (standard US door sizes, torsion vs extension springs, 10k/20k/30k-cycle ratings, R-value bands, opener HP by weight, wind-load zones). There are deliberately no door, opener or labor prices, no regional cost indexes and no installer directory — cost tools use the prices you enter — so the results stay valid over time.
Correctness is checked against known reference values (see the methodology and the numeric self-check). The formulas and their basis are documented under Sources & formulas. All results are planning estimates and equipment-sizing typicals: get itemized written quotes from licensed, insured garage-door installers. ⚠️ Garage-door springs and cables store extreme mechanical energy and can cause serious injury or death — spring, cable and off-track work is for a trained technician, never DIY. Hard-wired opener circuits are for a licensed electrician; sizing values are labeled typicals. Questions? Use the contact page.