Examples
Examples
Try the starting example
- Old recurring plan charge (USD)
- 100
- New recurring plan charge (USD)
- 160
- Billing period length (days)
- 30
- Remaining service days
- 12
- Prorated additional charge (USD)
- $24.00
- Old-plan unused value (USD)
- $40.00
- New-plan remaining value (USD)
- $64.00
Try another scenario
- Old recurring plan charge (USD)
- 100
- New recurring plan charge (USD)
- 160
- Billing period length (days)
- 30
- Remaining service days
- 18
- Prorated additional charge (USD)
- $36.00
- Old-plan unused value (USD)
- $60.00
- New-plan remaining value (USD)
- $96.00
Calculation method
Calculation method
Prorated additional charge (USD)
(b-a)*d/c
Old-plan unused value (USD)
a*d/c
New-plan remaining value (USD)
b*d/c
Symbols and units
- a
- Old recurring plan charge (USD)
- b
- New recurring plan charge (USD)
- c
- Billing period length (days)
- d
- Remaining service days
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- Actual-day proration within a single billing period; remaining days between zero and period days. Negative difference is a credit. Supported limits: All numeric inputs must be finite. Only the explicitly described mathematical scenario is supported.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.