What drives the cost

Why there are no figures here

Cost items are quantified by whoever knows their own institution's rates, the staff costs in their own country, and their own ethics committee's fees. Numbers written by someone who does not know them would be wrong, or right by accident.

What can be stated precisely is what drives the cost, and how the items relate to one another. The planner below holds the model, not the prices: you enter your own values and see the total, the breakdown and the sensitivity.

What it computes

To enrol, not to analyse. Expected dropout is applied in reverse: to end up with a given number of analysable people you must enrol more. This is the commonest error in longitudinal study budgets.

How many sensor kits are actually needed. Not one per participant. The number depends on each person's days of use, the study duration, and how realistically a kit can stay in circulation between return, cleaning and redeployment. Above 70% utilisation you are being optimistic.

Whether the coordination hours add up. The hours the protocol demands — participants times sessions, plus the overhead around each session — are compared with those funded by the staff entered. If they do not add up, a warning appears. It is a simple check missing from almost every budget.

What moves the total. Each parameter is raised by 10% and the effect is shown. The items at the top of the list are the ones worth arguing about; the rest is background noise.

How to use it

Values stay on this computer, in the browser, and are not sent anywhere. They can be exported to a file and reimported elsewhere, to hand to a colleague or attach to a proposal.

The currency selector changes only the symbol: no conversion is applied, because an exchange rate entered here would be out of date within a week.