Which interior design fee model actually pays you the most per hour?

Which fee model actually pays you the most per hour on this design project?

Enter a project's design hours, site visits, procurement items and meetings, then your rate for each fee model. See the effective hourly each model earns once scope creep is priced in, how much overrun each can absorb before dropping under your target, the fee you need and a walk-away fee. Paste past projects and see which fee model really paid you best.

Your numbers, not market rates and not advice. This page knows no going rates and gives no legal, tax or licensing advice: every hour, rate and budget is a number you type. Nothing is uploaded: the inputs are used in this browser tab only.

1. Your time on the project

Design hours (concepts, plans, revisions) Site visits Hours per visit Items to source, order and track Minutes per item Client meetings and calls Hours per meeting

Expected overrun on those hours (%) Stress overrun, the bad case (%) Target hourly rate ($) Walk-away floor (% of target)

2. The project and your rate for each fee model

Clear a rate box to leave that model out.

Client's total project cost ($) Product bought through you ($) Square feet

Hourly rate ($) Hourly write-off (%) Flat fee ($) Percent of project cost (%) Per square foot ($) Net product margin (%) Hybrid: flat design fee ($) Hybrid: product margin (%)

The comparison

Fee model	Bills	Effective hourly	At stress overrun	Overrun it can absorb

Effective hourly as the project overruns

Where the hours go

Work	Baseline hours

Hours are your own estimates multiplied out; real projects vary. A fee here is a starting point for your contract, not a promise.

3. Audit your past projects by fee model

One row per finished project: name, fee model (any label), total fee earned, hours you actually spent. Up to 300 projects.

By fee model

Model	Projects	Fee	Hours	Effective hourly

Projects, worst first

#	Project	Model	Fee	Hours	Effective hourly	Short of target

Prefer a CLI?

Same logic, zero dependencies, one command:

node cli.mjs compare --design-hours 50 --project-cost 60000 --overrun 40 --target 110
node cli.mjs history projects.csv --target 110 --json

Get cli.mjs and engine.mjs — Node 18+, nothing to install, no network call. More: How to choose an interior design fee structure.

What's recognised

Input	Handling

The answer is exact for the numbers you type. It does not know going rates, your local market, your contract terms, or how a client will actually behave.

Common questions

Is this a market rate or professional advice?

No. Every hour, rate, percentage and budget in the answer is a number you typed. It does not look up what other designers charge and gives no legal, tax or licensing advice. It does the arithmetic on your own time so you can see what each fee model would earn you.

Which interior design fee model is best?

It depends on your hours and how much the project overruns. Hourly protects you from scope creep because the client pays for the extra time; a flat fee, percent of cost, per square foot or product margin all keep the fee fixed while your hours grow. The calculator shows each model's effective hourly at your expected overrun and at a stress overrun, and how much overrun each can absorb before dropping below your target.

Does it upload my projects?

No. The browser page works on the numbers and text you enter, in your own browser, and never sends them anywhere. The CLI reads a local file or stdin and makes no network call.

How is the effective hourly calculated?

Baseline hours are design hours + site visits x hours each + items x minutes each + meetings x hours each. Expected hours add your overrun percent. Effective hourly = what the model bills / expected hours. Hourly bills your rate x hours less the write-off, so overrun does not lower it.

What is the walk-away fee?

Expected hours x a floor rate (a percent of your target, 75 percent by default). Below it the project costs you more than it is worth to you, so you decline or re-scope rather than discount.