Percentage Calculator

Rounding Rules Calculator

This calculator provides a rounded, discounted fare result when provided with an un-discounted fare price and a percentage discount value*.

* as defined in RSPS7001 02-06, Page 41.

Full Fare Amount (GBP)
Percentage Discount (without % sign)

Note: This only evaluates the rounding rules for the “Child/Railcard/ Other % discount” column in the “Single/Return – 1ST/STD Class” and “Season Tickets set explicitly by TOC -1ST/STD Class” rows.

Application of RSPS7001 02-06 Standard

RSPS7001 02-06, Page 41 states that to apply rounding on discounts, the following steps should be taken;

  1. 1. Multiply Adult Fare by % discount.
    (e.g. a 34% discount would be calculated by multiplying the adult fare by 0.66).
  2. 2. If result in Step 1 is not a multiple of 5p, round down to next multiple of 5p.

For example, a full fare costing £24.20 with a railcard 34% discount** would be worked out:

  1. 1. £24.20 * 0.66 = £15.972
  2. 2. £15.972 rounded down to nearest 5p = £15.95
**Source: RDG Standard RSPS7001 02-06


If using a system that only allows for 2 decimal places, there can be a discrepancy in certain results.

For example, £173.10 * 0.66 = £114.246

Using only 2 decimal places could result in rounding £114.246 to a final price of £114.25. Adhering to the standard should mean that .246 is rounded down to .20, resulting in the correctly rounded final amount of £114.20.

Therefore to conform to the RSPS7001 02-06 standard correctly, you must ensure that the system calculating the fare does not round up to 2 decimal places, before rounding down to the nearest 5p.

One potential example of this could include a spreadsheet with formatted cells set to “currency”.