Project Price (Fixed-Bid) Calculator
Quote a fixed price with confidence: your hours estimate at your rate, plus a buffer for the scope risk every fixed bid carries.
Written by Dorothy Ibrahim, 10+ years in banking & finance
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How we calculate this
This calculator turns an hours estimate and your hourly rate into a fixed price to quote a client. A fixed price transfers the risk of the work running long onto you, so it adds a complexity buffer on top of the base cost to cover that risk, then adds any pass-through costs like licenses or subcontractors. It also shows the effective hourly rate you actually earn if the estimate holds.
The formulas
- Base cost
- estimated hours × hourly rate
- Fixed-bid price
- base cost × (1 + complexity buffer%) + fixed costsThe buffer is the premium you charge for absorbing the client’s scope risk instead of billing hourly.
- Effective hourly
- fixed-bid price ÷ estimated hoursZero if estimated hours is zero.
Worked example
- With the defaults — 40 estimated hours at a $100/hour rate — the base cost is 40 × $100 = $4,000.
- A 20% complexity buffer adds $800 (4,000 × 0.20), bringing the padded cost to $4,800.
- No pass-through costs are added (fixed costs = $0), so the fixed-bid price stays $4,800.
- The effective hourly rate is $4,800 ÷ 40 hours = $120/hr — above the $100/hr input rate because of the buffer.
Rates, benchmarks & sources
- Base cost (hours × rate) plus a risk buffer plus pass-through costs. — Cost-plus project pricing methodology
- A complexity/scope buffer of roughly 15–30% is a common rule of thumb for absorbing overrun risk on fixed-price quotes. — Fixed-bid risk-premium practice for service work
Figures current as of 2026-07-02. See our methodology & editorial standards for how constants are versioned and verified.
What this tool doesn’t model
- Assumes the hours estimate is accurate — the buffer exists precisely because estimates often run long, but it does not guarantee the project stays on budget.
- Does not model milestone payments, deposits, or partial refunds; it produces a single total quote.
- Does not account for taxes or business overhead beyond what you build into your hourly rate.
Frequently asked questions
How do I price a fixed-bid freelance project?
Estimate the hours honestly, multiply by your hourly rate, then add a buffer for the risk that the work runs long. Add any pass-through costs like licenses, stock assets, or subcontractors on top. The buffer matters because with a fixed price, every hour over your estimate comes straight out of your effective rate.
What complexity buffer should I use?
For well-scoped, familiar work, 15% is often enough. For a new client, vague requirements, or unfamiliar tools, 25–30% or more is prudent. The buffer is not padding — it is the premium you charge for absorbing the client’s scope risk instead of billing hourly.
Fixed price or hourly — which should I quote?
A fixed price rewards efficiency and gives the client budget certainty, but you carry the risk of overruns. Hourly billing is safer for open-ended or evolving work. A common approach is to estimate hourly, then quote a fixed price derived from it with a buffer added.
How do I protect a fixed bid from scope creep?
Define deliverables and revision limits in writing so the scope is as fixed as the price. Bill anything beyond that agreed scope as a change order at your hourly rate rather than absorbing it for free — that is the mechanism that keeps a fixed price fair to both sides.
Should pass-through costs be included in my hourly rate instead?
No — bundling licenses, stock assets, or subcontractor costs into your rate quietly erodes your margin and hides them from the client. Listing them separately as fixed costs makes sure you recover them in full and keeps your effective hourly rate accurate.