Observed arrival · 2026-10-25
Trade Margin Lab’s Contractor Toolbox
A free set of plumbing, gas, HVAC, electrical, and job-profit calculators aimed at working contractors.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Plumbers, HVAC technicians, electricians, and contractors
- Worth noticing
- The 45° offset tool separates centerline travel from straight cut length after subtracting entered fitting takeoffs.
Field notes
The toolbox groups calculators by trade and includes a search field and a favorites-only option. The job-profit worksheet separates labor, materials, other direct costs, and allocated overhead before showing estimated profit, margin, and break-even price. Several tools include scope limits: the duct calculator is not a Manual J load or duct design, and the pipe and gas tools do not certify code-compliant sizing.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue