March 18, 2026·4 min read

How to Calculate Markup as a Contractor (The Right Way)

Most contractors confuse markup and margin and end up undercharging. Here's the correct way to calculate markup so you stay profitable.

How to Calculate Markup as a Contractor (The Right Way)

One of the most expensive mistakes contractors make is confusing markup and margin. It's a math error that quietly destroys profit on every job.

Markup vs. Margin — What's the Difference?

Markup is a percentage added to your costs. Margin is the percentage of the selling price that is profit.

They are not the same number. Here's where most contractors go wrong:

If your job costs $10,000 and you want to make 20% profit, you do NOT charge $12,000.

Why? Because $12,000 with a $10,000 cost gives you $2,000 profit — but $2,000 ÷ $12,000 = 16.7% margin. Not 20%.

The Correct Formula

To achieve a 20% margin, you need a 25% markup.

The formula: Selling Price = Cost ÷ (1 - Desired Margin)

Desired Margin Required Markup
10% 11.1%
15% 17.6%
20% 25%
25% 33.3%
30% 42.9%
33% 49.3%

A Real Example

You're quoting a painting job:

  • Materials: $2,400
  • Labor: $3,800
  • Total Cost: $6,200

You want 25% margin. What do you charge?

$6,200 ÷ (1 - 0.25) = $6,200 ÷ 0.75 = $8,267

If you had just added 25%: $6,200 × 1.25 = $7,750 — that's $517 less than you need.

Over 50 jobs a year, that error costs you $25,000.

What About Overhead?

Overhead needs to be in your cost basis before you calculate markup. Overhead includes:

  • Truck payment and insurance
  • Tools and equipment
  • Office and admin costs
  • Your own salary (if you're working the job)
  • Marketing costs
  • Software subscriptions

Most contractors calculate their overhead as a percentage of revenue — typically 15–25% — and add it to job costs before marking up.

Don't Do This Math in Your Head

This is why ContractorQuoteKit has a built-in markup calculator. Enter your costs, set your markup percentage, and it calculates your total automatically — correctly.

It also exports a clean PDF proposal with all the numbers clearly displayed, which builds trust with clients and helps you justify your pricing.

Try it free at contractorquotekit.com.

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