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A 50% markup is only a 33% margin — and after overhead, the $75k kitchen nets $17,000. The confusion between the two bankrupts contractors.
The most expensive confusion in contracting is markup versus margin: 1.5× markup on $50,000 of direct cost is a $75,000 contract — but that is a 33.3% gross MARGIN, and after the $8,000 overhead share the job nets $17,000, not the $25,000 the markup number promised. This calculator prices the remodel honestly: direct costs, markup, change orders, overhead, and the net percentage that tells you whether the price survives the surprises.
Remodelers use it before signing the contract: 1.5× on $50k direct is a 33% margin — $17k net after overhead — and the markup-vs-margin confusion is where busy contractors go broke.
Residential remodeling runs 1.5–1.67× on direct cost (a 33–40% gross margin), with design-build firms higher because design hours are real cost. The markup must fund three things: overhead (office, insurance, trucks, estimating hours, warranty reserve), profit, and the slippage between estimate and reality — hidden rot, code upgrades, and the client changes that never quite get billed. Contractors running 1.35× survive only with surgical estimating and low overhead; below that you are busy and broke. The confusion that kills: markup ≠ margin — a 50% markup yields a 33% margin (markup divides by cost; margin divides by price), so "I charge 50%" means you keep 33 cents of every dollar BEFORE overhead. The disciplines that protect it: change orders at full markup signed BEFORE the work, a payment schedule that never lets receivables exceed work-in-place (deposit 25–33%, milestone draws, final 10% at substantial completion), honest allowances (lowball allowances make pretty bids and ugly change orders), and a 1–2% warranty reserve — callbacks are certain, the only question is whether you priced them.
From your own job-cost history, by task type — never from new-construction brain. The asymmetry that wrecks remodel estimates: subs quote and materials invoice, but YOUR crew's labor drifts 15–25% on remodels because existing conditions never match assumptions (the wall that was supposed to open cleanly has knob-and-tube; the floor is not level; the plumbing stack is galvanized). Track actual hours per task type on every job — demo, framing, tile, trim-out — and estimate from YOUR averages, padded. The estimating process that filters profit from charity: site visit with photos and measurements, scope document line by line (what IS included), exclusions named (what is NOT), allowances stated at real mid-grade numbers, and a validity window because supplier prices move. Charge for the deep work: pre-construction agreements ($1,500–5,000 for design and detailed estimating on real projects) filter tire-kickers and pay for the 20 hours every serious bid costs — homeowners who balk at paying for a real estimate were never going to pay for a real remodel. And the license floor: contractor licensing, permit responsibility, and certificates of insurance from every sub — one uninsured sub injury reaches through to you.
As margin protection, not awkwardness — the change order is a normal business document, and the contractors who treat it as confrontation are the ones absorbing $4,000 of "while you're at it" per job. The rules: every change priced in writing at full markup BEFORE the work starts (verbal approvals evaporate at final invoice), the schedule impact stated alongside the price ("adds 3 days" matters as much as "adds $850"), and a signature — a text reply counts if your contract says so. The psychology that makes it easy: present changes as choices, not problems — "We found galvanized supply lines behind the tub wall; replacing them while we're in there is $1,400, leaving them is zero but they'll fail eventually — which would you like?" Homeowners choose upgrades happily when informed; they revolt over surprise line items at the end. Track change-order percentage per job (changes ÷ original contract): 5–10% is a healthy remodel; over 20% means your estimating missed scope, and the fix is in the pre-construction process, not the client. The final-invoice protection: substantial-completion walkthrough with a signed punch list — payment and the punch list happen together, not the list first and the check whenever.