Contractor Tools
Nineteen Calculators and Document Generators, Built for the Trade and Not for Homeowners
Contractors lose money in two places: a job priced on the wrong markup, and paperwork that leaves the change order unsigned. These tools cover both, plus the span and sizing checks a crew needs before the wall comes out.
Every figure is read from a published source and the source is named on the page. Nothing you type is stored, sent, or attached to an account.
Pricing and profit math
Seven calculators for the numbers that decide whether a job makes money: markup versus margin, real labor cost, overhead per billable hour, break-even volume, and what a lead can cost before the job stops paying.
Markup & Margin Calculator for Contractors
Turn a markup into the margin it really is, and find the markup that hits your net-profit target.
Open tool →Labor Burden Calculator
The true hourly cost of an employee — taxes, comp, benefits and PTO on top of the wage, for all 50 states.
Open tool →Overhead Calculator for Contractors
Total your annual overhead and see what every billable hour has to carry.
Open tool →Break-Even Calculator for Contractors
How many jobs a month keep the lights on — and how many hit your profit target.
Open tool →Cost per Lead Calculator
Your maximum profitable cost per lead, checked against national channel benchmarks.
Open tool →Contractor Marketing Budget Calculator
A revenue-based marketing budget, and the leads and jobs it should buy.
Open tool →Construction Cost Estimator
NAHB-based planning range for new construction by state, size, finish level and foundation.
Open tool →Client paperwork that prints clean
Five generators for the documents a job actually needs. Fill in the fields, print or save as PDF. The document prints on its own, without the form or the site around it.
Contractor Estimate Generator
Build a clean, printable estimate with sectioned line items, deposit and payment terms.
Open tool →Construction Bid Proposal Generator
A signed-ready bid: scope, exclusions, allowances, alternates and validity.
Open tool →Change Order Generator
Price the change, add the days, get it signed before the work starts.
Open tool →Construction Schedule Generator
Phase-by-phase schedule with a printable Gantt — workdays only, end date included.
Open tool →Lien Waiver Generator
State-correct lien waivers — the statutory form where your state prescribes one.
Open tool →Span and sizing checks from the code tables
Five lookups that answer the question a framing crew asks on site. Values come from the published tables, and every answer names the table it came from. Where the code does not tabulate a case, the tool says so.
Floor Joist Span Calculator — IRC 2021
IRC 2021 span checks for wall-removal and addition framing, straight from the code tables.
Open tool →Beam Span Calculator — IRC 2021
Girder and beam sizing from the IRC 2021 header tables.
Open tool →Header Size Calculator — IRC 2021
Header sizing for exterior, interior and porch openings per IRC 2021 R602.7.
Open tool →Rafter Span Calculator — IRC 2021
Rafter spans by snow load, species and spacing from IRC 2021 R802.4.1.
Open tool →Deck Footing Size Calculator — DCA 6
Footing diameter and thickness from the DCA 6 prescriptive tables.
Open tool →Concrete takeoffs
Two takeoffs for the pour: volume with waste and truck loads, and the bar schedule for a slab on grade.
The tools are free. Filling the calendar is the harder part.
Zainfy runs SEO, web design and social for home remodeling and construction contractors across the United States, with a 90-day results guarantee. If the math above says you need more jobs at a lower cost per lead, that is the work we do.