Annual vs Monthly Subscription Calculator: Is the Discount Worth It?

Compare a first-year scenario, not a pricing forecast

The tool compares the same starting accounts under monthly payments or one upfront annual charge. There are no new customers, upgrades or reactivation. Annual accounts receive twelve months of service. A fixed refund allowance is applied to billed value for both plans, without reducing original fees or service costs. Enter anonymous figures in one currency excluding tax.

Monthly survivors pay at the start of each period and churn afterward. Expected payer counts can be fractional and are not actual invoices. The model excludes year-two renewal, acquisition costs, fixed overhead, failed payments, tax, financing and discounting. It is not recognized revenue, profit, lifetime value or a causal estimate of annual billing.

Inspect the formulas and rounding

Annual price is 12 × monthly list price × (1 − discount). Round half-up to two currency decimals once per account using integer cents and discount basis points. Expected monthly payers in month m are N × (1 − churn)^(m − 1). Sum all twelve periods; do not round people before calculating the expectation.

Monthly contribution = billed value × (1 − percentage fee − refund allowance) − expected payments × (fixed fee + service cost). Annual contribution = annual billed value × (1 − percentage fee − refund allowance) − annual fixed fees − N × 12 × service cost. Percentage inputs are divided by 100. A zero annual price generates no positive charge and no fixed payment fee.

The difference is annual minus monthly contribution. Gross first-payment cash difference is annual billed value minus the starting cohort's first monthly bill. It excludes fees, reserves, costs and actual settlement timing; do not treat it as spendable profit. Expected totals remain unrounded until display. The exported JSON retains full precision and the assumptions.

Known-answer example

The synthetic defaults are 100 accounts, price 100, annual discount 20%, churn 0%, service cost 10, fee 3%, fixed fee 0.30 and refund allowance 2%. Annual price 960; monthly billed value 120,000; annual billed value 96,000; monthly contribution 101,640; annual contribution 79,170; difference −22,470; gross first-payment cash difference 86,000.

At 100% after-payment monthly churn, all starting accounts still make the first payment and none make the next eleven. At 0% churn, all make twelve payments. These are boundary cases, not plausible forecasts. A 100% annual discount means no upfront charge while twelve-month service cost remains. Negative values remain visible.

Use and export responsibly

Changing any input clears the previous result. Reset restores synthetic numbers; check your scope note. Copy or download the complete scenario. Expand the twelve-month path to inspect the expected payer count and cumulative contribution. The annual path deducts fees and allowance at the start, then accumulates service costs; refund timing is not modeled.

Use measured survival or explicit sensitivities, not generic churn benchmarks. Different monthly and annual buyer types, service costs, refund policies or payment failures require a richer model. A positive contribution difference does not establish willingness to pay or authorize a new offer.

Sources and limitations

Checked October 21, 2026: ChartMogul's current pricing page presents monthly and annual options; this is a qualitative commercial example, not demand volume or a discount benchmark. Stripe's subscription revenue-recognition documentation separates recognition over service periods from subscription status. Paddle's billing-cycle guide was published June 29, 2021; it is historical background, not a new release. This original scenario method does not reproduce a provider's accounting engine or guarantee retention, profit or sales.