Is this a real S-curve?

No, and the tool states so. It assumes evenly linear monthly certified progress — a planning simplification, not a schedule-driven S-curve.

What is peak negative exposure?

The cash the contractor is expected to fund before payments catch up: monthly cost outflow multiplied by the combined certification and payment lag, less the advance payment.

What is the cost-to-value ratio?

The share of each certified amount that leaves as cost. You enter it from your own commercial position; the tool assumes no margin.

Can it produce a bank-ready forecast?

It is a preliminary planning estimate. A funding submission should be built on the actual programme and the certified payment history.

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Contractors lose money on profitable projects when payment lags exceed working capital. This Professional calculator turns contract value, duration, advance and retention percentages and your certification and payment lags into a monthly picture, including the peak negative exposure the project is likely to demand.

Method and assumptions

monthly certified value = contract value / duration
monthly cost outflow = monthly certified value × cost-to-value ratio
monthly net cash in = monthly certified value − advance recovery − retention
peak negative exposure = monthly cost outflow × (certification lag + payment lag) − advance payment

The model assumes evenly linear monthly certified progress over the project duration; a planning simplification, not an actual S-curve.
All percentages and inputs are user-defined; the calculation is purely arithmetic and assumes no particular code or specification.
A preliminary decision-support estimate: the result does not replace an approved design calculation or review by a competent authority.

Frequently asked questions

Is this a real S-curve?: No, and the tool states so. It assumes evenly linear monthly certified progress — a planning simplification, not a schedule-driven S-curve.
What is peak negative exposure?: The cash the contractor is expected to fund before payments catch up: monthly cost outflow multiplied by the combined certification and payment lag, less the advance payment.
What is the cost-to-value ratio?: The share of each certified amount that leaves as cost. You enter it from your own commercial position; the tool assumes no margin.
Can it produce a bank-ready forecast?: It is a preliminary planning estimate. A funding submission should be built on the actual programme and the certified payment history.

13-Week Cash ForecastProject Control
Earned ValueProject Control
Cost-to-CompleteProject Control

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