How to price extra work with a scope change calculator
A worked $6,000 website example: estimate an added fee, understand delivery margin, and turn the number into a clear client quote.
A scope change calculator is useful when a fixed-fee project grows after the price has been agreed. It gives you a starting number for the added work. The final quote still needs a description, assumptions and a delivery decision. Here is how to use Clearcut’s free calculator without confusing an estimate with an accepted change.
Start with four checked inputs
Use the original fee, planned delivery hours, estimated delivery cost per hour and extra hours requested. Include coordination, production, testing and review in the hours. The delivery cost is your cost of doing the work, not your client billing rate.
For an illustrative website, enter a $6,000 fee, 80 planned hours, $45 delivery cost per hour and 16 extra hours. The baseline delivery cost is $3,600, leaving $2,400 before costs excluded from the estimate.
- Original fee: $6,000
- Planned hours: 80; extra hours: 16
- Estimated delivery cost: $45 per hour
Read the result correctly
The original delivery margin is ($6,000 − $3,600) ÷ $6,000 = 40%. The extra delivery cost is 16 × $45 = $720. Absorbing that work reduces the estimated margin to 28%.
The calculator suggests $6,000 × 16 ÷ 80 = $1,200 for the addition. With a $7,200 total fee and $4,320 delivery cost, the estimated margin returns to 40%. This assumes the same hourly cost for the added work. It is not a market-price recommendation or a guarantee of profit.
- Include overhead in the cost figure if you want it modeled
- Re-estimate if the addition needs a more expensive specialist
- Use a fresh baseline if the original estimate was unrealistic
Turn the estimate into a decision
Download the estimate for your own review. Then describe the added deliverable in a client quote: three service pages using the agreed layout, supplied copy, one review round and the proposed delivery effect. Keep internal cost assumptions separate.
Clearcut’s free quote starter lets you write that proposal without an account. Do not begin on the assumption that producing a quote means the client accepted it. Record the actual answer through your normal agreement process.
- Define the output and exclusions
- Choose the final fee and timing
- Ask for an explicit decision before scheduling