Change Order Margin Analyzer

What Is a Change Order?

A change order is a modification to the original contract scope — additional work, deleted work, or changed conditions that alter what was agreed to at the start of the job. Change orders are a normal part of construction. What is not normal is pricing them correctly under pressure.

When an owner or GC hands a contractor a change order request, the clock is usually running. There is a job to keep moving, a relationship to manage, and a number to produce quickly. Most contractors reach for a rule of thumb — apply a 20% markup, or 25%, or whatever feels right in the moment — and move on. The problem is that a markup on direct costs is not the same thing as a margin on the selling price, and when overhead is factored in, a quick markup often produces a price that fails to recover full costs.

Markup vs. Margin

This is the single most important distinction in change order pricing and one of the most commonly confused.

A markup is applied to cost and expressed as a percentage of cost. A 25% markup on $10,000 in direct costs produces a price of $12,500.

A margin is expressed as a percentage of the selling price. A 20% margin means that 20 cents of every revenue dollar is gross profit. To achieve a 20% margin, you divide your total cost by (1 minus 0.20), or 0.80.

If you have $10,000 in direct costs plus $2,500 in overhead for a total cost of $12,500, and you want a 20% gross margin, the correct price is $12,500 / 0.80 = $15,625. A contractor who applies a 20% markup to the $10,000 in direct costs alone charges $12,000 — which does not even cover overhead, let alone generate profit.

The calculator shows both the mathematically correct price and what a quick markup produces, so you can see the gap before you submit the number.

What This Calculator Includes

The calculator builds your change order price from four cost components and two overhead and profit inputs.

Labor is entered as estimated hours multiplied by your fully-loaded burden rate — not your base wage. If you use base wages here you will systematically underprice every change order. Use the Labor Burden Rate Builder on this site to calculate your fully-loaded rate.

Materials, subcontractor costs, and equipment are entered as actual costs. For materials, use your supplier invoice cost. For subcontractors, use the sub's price to you before any markup.

Overhead is applied as a percentage of total direct costs. Your overhead rate should reflect all of your indirect costs — supervision, insurance, office, vehicles, and any other cost that is not directly assignable to a specific job. Most contractors run overhead between 10% and 20% of direct costs, though this varies significantly by company size and structure.

Target gross margin is the margin percentage you want to earn on this change order after all costs including overhead. The calculator converts this to the correct minimum selling price.

Why Change Orders Often Lose Money

Three patterns consistently erode change order margins:

Pricing on direct costs only. Overhead does not disappear on a change order. If your overhead rate is 20% and you price a change order without adding overhead, you are absorbing that cost silently.

Confusing markup with margin. As shown above, a 20% markup and a 20% margin are not the same thing. The margin approach produces a higher price that actually achieves the target.

Underestimating labor hours. Change order work is frequently performed under disrupted conditions — out of sequence, with incomplete information, with different crews than originally planned. The productivity assumption that works for base contract work often does not hold on change orders. Build in a productivity factor for disrupted conditions.