Billing Proration Scenario Calculator

How to use Billing Proration Scenario Calculator

Intersect an active half-open interval with the full billing period. Price times the exact covered-duration fraction gives the prorated amount; rounding is performed once under the selected decimal policy.

1. Enter full-period start, full-period end (excluded), active start, active end (excluded), full-period price, output decimal places.
2. Choose the stated convention and check the units and supported model.
3. Calculate, inspect the result, then copy or download it.

Good to know

• Positive billing period up to366days; valid date-only calendar days or explicit-offset instants for elapsed seconds. Nonnegative plain-decimal price up to1trillion,0–6 decimal places. No provider, tax, legal credit/refund or automatic30-day-month assumption.
• Runs locally. Text/JSON fields are capped at30,000 characters; stricter page-specific and numeric-string limits also apply. Numeric inputs are bounded to magnitude1e15 and nonzero magnitude at least1e-100 unless an exact-string mode states otherwise. Approximate summaries use12 significant digits; CSV numeric cells retain the complete stored value and potentially formula-like string cells gain a protective apostrophe; unsupported, non-finite or detected underflow states return an error.
• Educational user-assumption arithmetic only. No live prices, laws, tax rules, quotes or financial advice.