Calculate MRR from the Stripe API

Updated 2026-08-04

Stripe has no MRR endpoint. You build it from active subscriptions.

The approach

1. List subscriptions with status=active
2. Expand price data so you get amount and interval in one call
3. Normalise each line to a monthly figure
4. Sum

The code

type Interval = "day" | "week" | "month" | "year";

const MONTHS_PER: Record<Interval, number> = {
  day: 12 / 365,
  week: 12 / 52,
  month: 1,
  year: 12,
};

/** Monthly contribution of a recurring charge. */
function toMonthly(amount: number, interval: Interval, count = 1): number {
  const cycles = MONTHS_PER[interval] * Math.max(1, count);
  return cycles > 0 ? amount / cycles : 0;
}

/** Stripe reports minor units. Not every currency has two decimals. */
function fromMinor(amount: number, currency = "usd"): number {
  const zeroDecimal = new Set(["jpy", "krw", "vnd", "clp", "isk"]);
  return zeroDecimal.has(currency.toLowerCase()) ? amount : amount / 100;
}

async function trueMrr(key: string): Promise<number> {
  let mrr = 0;
  let startingAfter: string | undefined;

  for (;;) {
    const qs = new URLSearchParams({
      status: "active",
      limit: "100",
      "expand[]": "data.items.data.price",
    });
    if (startingAfter) qs.set("starting_after", startingAfter);

    const res = await fetch(`https://api.stripe.com/v1/subscriptions?${qs}`, {
      headers: { Authorization: `Bearer ${key}` },
    });
    if (!res.ok) throw new Error(`stripe ${res.status}`);
    const page = await res.json();

    for (const sub of page.data) {
      for (const item of sub.items.data) {
        const price = item.price;
        if (!price?.recurring || price.unit_amount == null) continue;
        const major = fromMinor(price.unit_amount, price.currency);
        mrr += toMonthly(major, price.recurring.interval,
                         price.recurring.interval_count || 1)
               * (item.quantity ?? 1);
      }
    }

    if (!page.has_more) break;
    startingAfter = page.data[page.data.length - 1].id;
  }

  return mrr;
}

The four traps

Pagination. Stripe returns 10 by default, 100 maximum. Miss the has_more loop and everything past your first page silently vanishes. This is the most common bug in homegrown MRR scripts, and it fails quietly — your number is just wrong.

Minor units. Stripe reports cents, so you divide by 100 — except for zero-decimal currencies like JPY and KRW, where you must not. Get this wrong and your yen revenue is 100× too small.

Quantity. A subscription item can have quantity > 1 for seat-based pricing. Ignoring it undercounts every multi-seat customer.

Multiple items. One subscription can carry several items — a base plan plus add-ons. Reading only items.data[0] misses the rest.

Status filtering

status=active excludes trialling, past-due and cancelled subscriptions, which is what you want. See what counts as an active subscription for the reasoning, particularly around past-due.

Permissions

A restricted key with read on Subscriptions, Prices and Products is enough for this. Nothing needs write access. Full list: Stripe key permissions for reporting.

If you'd rather not maintain this

The code above is roughly what FRGMNT's Stripe adapter does — and then the same toMonthly runs against Lemon Squeezy, Paddle and the rest, because the normalisation is platform-independent. See normalising subscription intervals in code, or query it from the terminal.