By Vellora Labs · Updated October 11, 2026
A study budget is a set of assumptions. Make the assumptions visible so another person can change them and reproduce the total. The example below uses our calculator’s current formula; every number is hypothetical.
Separate completed sessions from booked time.
Incentives in this model cover completed sessions. Staff time reserves every booked slot, including expected no-shows. This is deliberately conservative about calendar time, but it excludes cancellation payments unless you add them yourself.
Bookings = round up(target completions ÷ (1 − assumed no-show rate)). This estimates capacity under an attendance assumption. It does not guarantee that many completions; attendance and eligibility can differ from your expectation.
A fictional USD example you can reproduce
| Input | Assumption |
|---|---|
| Target completed sessions | 8 |
| Incentive per completed session | $50 |
| Session duration | 45 minutes |
| Assumed no-show rate | 20% |
| Planning / analysis time | 3 hours / 6 hours |
| Blended staff rate | $75 per hour |
| Software and recruitment fees entered | $100 |
| Contingency | 10% |
Book ceil(8 ÷ 0.8) = 10 slots. Reserve 10 × 45 ÷ 60 = 7.5 session hours. The calculator treats its hourly rate as the total rate for the staff time being budgeted; if two people attend, include both people’s cost in the blended rate or calculate their time separately.
| Cost | Calculation | Amount |
|---|---|---|
| Incentives | 8 × $50 | $400.00 |
| Staff time | (7.5 + 3 + 6) × $75 | $1,237.50 |
| Other entered fees | Supplied assumption | $100.00 |
| Subtotal | $400 + $1,237.50 + $100 | $1,737.50 |
| Contingency | 10% × $1,737.50 | $173.75 |
| Total | Subtotal + contingency | $1,911.25 |
Change one uncertain input at a time.
| No-show assumption | Slots to book | Total with other inputs unchanged |
|---|---|---|
| 0% | 8 | $1,787.50 |
| 20% | 10 | $1,911.25 |
| 40% | 14 | $2,158.75 |
The discontinuities come from rounding up whole bookings. These are planning scenarios, not measured no-show benchmarks. A higher attendance risk may also change recruiting effort, which this example holds fixed to show the calculation clearly.
Costs this total can miss
- Recruitment screening, scheduling and rescheduling time.
- Incentives for partial sessions or cancellations under your actual policy.
- Extra staff, interpreters, accessibility support and transcription review.
- Taxes, payment fees and currency conversion.
- Additional software seats, storage or research-platform charges.
Add known costs to the correct inputs or maintain a separate line-item estimate. Do not use contingency to conceal a known expense. Check actual supplier terms before committing; this is not a vendor quote or market-rate recommendation.
Review the budget with the study plan.
Save the input values, formula version, currency and date alongside the decision the study supports. Update both the expected attendance and the cost model after a pilot. Use the budget calculator to reproduce this example, then keep a record of changes and their reason.
For recruitment preparation, use the screener builder. The evidence log is for observations and findings; keep participant payment and identifying details in an appropriately controlled system.