Rate Calculation

Bookyt Team
May 18, 2026
3 min read
Bookyt

If you keep a rented item, such as a vehicle, longer than originally planned, this creates what is known as an overrun period. To keep everything fair, an additional charge is calculated, which is explained here in simple terms.

Basic concept

The regular end time is the point by which the item should have been returned. If it is returned later, the overrun period is calculated.

Multiple components

The overrun period can be calculated using different time components:

  • a full day
  • a week
  • a calendar day (any started day is counted in full)
  • an hour
  • a month
  • a year

This lets you choose the right component for every situation.

“Greedy” method

We look at how much additional time was used and check whether there is already a larger time component for it, such as a week. If not, we use a smaller component, such as a day. This allows us to cover the entire overrun period step by step.

Cost per component

Each time component has a defined price. Sometimes there are different prices for certain days, such as a surcharge for weekends or public holidays. The sum of these components forms the overrun amount.

Examples

Assumed overrun period: 3 days and 4 hours.

  • A component for one day costs 10 euros.
  • Another component for one hour costs 1 euro.

The calculation is:

  • 3 days × 10 euros = 30 euros
  • 4 hours × 1 euro = 4 euros

Total: 34 euros for the overrun period.

Calendar day

When calculating a calendar day, every started day is counted in full. So if someone rents from Monday at 11:30 a.m. until Tuesday at 12:30 p.m., this counts as 2 calendar days, even though it is only slightly more than 24 hours.

Other time units

If you only have a component for one day, but the customer returns five hours late, you can simply charge a full day if no other component has been configured. If hourly billing were also available, however, the 5 hours would be billed. This therefore depends on the defined components.

Why the

system is designed this way

  • Flexibility: Whether someone is only a few minutes late or many days late, there is always a suitable time component.
  • Fairness: Someone who only exceeds the rental period briefly pays less than someone who rents for several extra days.
  • Clarity: The billing is divided into different components so it is clear how the additional amount is made up.

Conclusion

The overrun calculation is created when the agreed rental period is exceeded. Each additional time span is covered using defined time components. Each component has its fixed price. Depending on how long the additional time lasts, one or more of these components are added together. The result is the overrun amount that you pay in addition to the normal rental costs.

Last updated on May 18, 2026