Work out retention money instantly with clear inputs, formula shown and shareable results.
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.
Retention held
Held = min(certified value x retention rate, contract sum x limit)
Release
Half at practical completion, half after the defects liability period
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.
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.
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.