What a renewal price increase costs over the contract, what capping it saves, and the last day to give notice.
Arithmetic only — not tax, accounting, legal or investment advice. Check against current rules.
Renewal uplift and notice date: Each renewal is rounded to a whole minor unit as an invoice would be, and the next rise applies to the invoiced price. The notice deadline is the renewal date minus the notice days.
Quoted from the toolbelt spec, the document this tool was built against.
Negatives are parenthesized because that’s what a statement does. The rest is four promises.
Amounts are integers in the currency's smallest unit, end to end. A float never touches a cent.
Rounded once, at the end. Rounding each operand is how a split stops summing to the whole.
The arithmetic lives in one unit-tested module, and the extension uses the same one.
There is no request to make. What you type stays in this tab and is gone when you close it.
A calculator answers the question once. These carry the answer into a product, name what it computed, and argue the method.
Worked example. Type over it.
Result
60 days from 2026-10-25. Open the negotiation well before it, while saying no is still possible.
| Renewal | At the uplift | Held to 3.0% |
|---|---|---|
| 1 | 25,920.00 | 24,720.00 |
| 2 | 27,993.60 | 25,461.60 |
| 3 | 30,233.09 | 26,225.45 |
Each renewal is rounded to a whole cent, like the invoice, and the next rise applies to that invoiced price. Some contracts cap increases; read yours before you assume a rate.