Free Invoice Generator

Retainer calculator

A retainer states a fee and the hours it covers, but not what you earned per hour once the month is over. That figure moves with every hour you work, and this page works it out.

The agreement

What the client pays every month, whether the work turns up or not.

What the agreement says the fee is for. Leave it empty if yours doesn't name a number. The effective rate still works; there's just nothing to compare it to.

How the month went

Everything the client got, not only what was logged against the brief. Calls, revisions and message threads all take hours, whether or not anyone paid for them.

What you charge per hour beyond the included ones. Leave it empty if your agreement has no overage clause, and the page will show you what that costs.

Used only if you press Create this invoice, as the name of the line it becomes.

GuideHow retainers workHow this works, and where the figures go wrong →

What the retainer calculator does not do

  • It doesn't suggest a fee or a number of hours. That's why neither field has quick-fill buttons. What a retainer is worth depends on your work and your client, and this page knows neither.
  • It doesn't track a prepaid balance across several months. That's a different arrangement (money paid up front and drawn down per job), and the invoice calculator already does it with a deposit against the lines.
  • It doesn't know which hours count. Calls, revisions, scoping and long message threads often go untracked but still lower the effective rate. I recommend counting them here.
  • It doesn't keep anything. Nothing is written to your browser's storage while you use it and nothing is sent to us, so the figures are gone when you close the tab. Press Create this invoice if you need a document: the fee and any overage are handed to the invoice generator in this tab, cleared as soon as it opens, and saved there as a new invoice alongside any you already have.

Related

To check the rate this month implies against the one your year needs, use the freelance rate calculator. For how many hours a year holds once time off is out of it, use the billable hours calculator. To invoice hours at a rate rather than a fixed fee, use the hourly invoice calculator. For a retainer that starts or stops part-way through a month, the pro-rata calculator works out that month's share of the fee.

Last updated 21 September 2026