How to use this calculator
Enter the total period (in years), the discount rate, and the replacement interval. Optionally enter the unit cost to get the total present value. The calculator returns the multiplier for an item bought once every a years over a total period of b years: it sums the discount factor (1 + r)−t at each replacement time t = a, 2a, 3a, … up to the highest multiple of a that is ≤ b. Tick “immediate purchase” to include a £1 contribution at t = 0 (i.e. the first item is being bought now). For a schedule of several recurring items on different cycles, use the item-by-item build-up below the single calculator: add a row per item and the table totals each item's cost × its own multiplier.

Multipliers for Fixed Periods and Intervals

Multipliers for a pecuniary loss paid for a fixed period (and at intervals other than yearly) at a chosen discount rate. Computed live from the formula, so any term and rate is supported — not limited to those in published tables.


Item-by-item build-up (aids & appliances)

For a schedule of recurring items — wheelchairs, prostheses, hearing aids and batteries — each replaced on its own cycle. Set the total period and discount rate once, add a row per item, and the table looks up each item's multiplier and totals the lot.

# Item Unit cost (£) Replace every (yrs) Applies for Buy now? Multiplier Item total
Grand total