Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Net benefit of annual
$86.98
Headline saving
$98.00
Effective discount
16.7%
Cost of cash tied up
$11.03
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter monthly price ($).
- 2Enter annual price ($).
- 3Enter return on your cash (%).
- 4Read your net benefit of annual on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Annual plans discount 10–20% but lock up cash. This compares the saving to what the same cash would earn, and shows the effective return on prepaying.
Worked example
Using the values the calculator loads with:
Inputs
- Monthly price: 49 $
- Annual price: 490 $
- Return on your cash: 4.5 %
Results
- Net benefit of annual: $86.98
- Headline saving: $98.00
- Effective discount: 16.7%
- Cost of cash tied up: $11.03
What each field means
Inputs
- Monthly price ($)
- The monthly price used in the calculation, measured in $. Starts at 49 $ so you have a working example on load.
- Annual price ($)
- The annual price used in the calculation, measured in $. Starts at 490 $ so you have a working example on load.
- Return on your cash (%)
- The return on your cash used in the calculation, measured in %. Starts at 4.5 % so you have a working example on load.
Results
- Net benefit of annual
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Headline saving
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Effective discount
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Cost of cash tied up
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the annual vs monthly billing calculator work?
Annual plans discount 10–20% but lock up cash. This compares the saving to what the same cash would earn, and shows the effective return on prepaying. The underlying maths is: Net = (monthly × 12 − annual) − annual × return × 0.5.
What do I need to enter?
3 values: monthly price, annual price, and return on your cash. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the net benefit of annual result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Annual vs Monthly Billing Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/annual-vs-monthly-billing
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/annual-vs-monthly-billing" target="_blank" rel="noopener">Annual vs Monthly Billing Calculator — RevenueLab</a> (2026).</p>
Source: [Annual vs Monthly Billing Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/annual-vs-monthly-billing) (2026).