Retention Money Calculator

Work out retention money instantly with clear inputs, formula shown and shareable results.

About Retention Money Calculator

Retention is deducted from each interim certificate at the contract rate, commonly five percent, but subject to an overall cap expressed as a percentage of the contract sum, commonly 2.5 percent. Half the retention is normally released at practical completion and the balance at the end of the defects liability period.

Formulas

Retention held

Held = min(certified value x retention rate, contract sum x limit)

Release

Half at practical completion, half after the defects liability period

Worked example

With the default values below, Retention Money Calculator returns Retention held of $100,000.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Value certified to dateminimum 0: 2,000,000
Retention rateaccepts 0–20 %: 5 %
Contract summinimum 0.01: 10,000,000
Retention limitaccepts 0.1–10 %: 2.5 %

Results

Retention held: $100,000.00
Net value payable: $1,900,000.00
Retention cap: $250,000.00
Released at practical completion: $50,000.00

Step by step

1Values used
2Retention held
3Release
4Retention held= 100,000.00
5Net value payable= 1,900,000.00
6Retention cap= 250,000.00
7Released at practical completion= 50,000.00

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Retention Money figure worked out?

Held = min(certified value x retention rate, contract sum x limit). Retention is deducted from each interim certificate at the contract rate, commonly five percent, but subject to an overall cap expressed as a percentage of the contract sum, commonly 2.5 percent.

When does the cap start to bite?

Once certified value reaches the limit divided by the rate: at 5 percent retention capped at 2.5 percent, that is half the contract sum. Beyond that point no further retention is deducted.

What values do I need to enter?

This calculator takes 4 inputs: Value certified to date, Retention rate, Contract sum, Retention limit. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.