Invoice Aging Calculator

Dates: YYYY-MM-DD or MM/DD/YYYY. Amounts may carry a currency symbol and thousands commas ($1,200.50). Blank lines are ignored; anything else that cannot be read is listed back at you by line number, never dropped in silence.
Defaults to today. Set it to a month-end for a closing snapshot.
Formatting only — no currency conversion. Paste one currency at a time.
About this page

What is invoice aging?

Invoice aging sorts unpaid invoices by how long they have been outstanding; this calculator ages each one from its due date. An aging report groups your open (unpaid) invoices by how long each one has been past due, so you can see at a glance how much of your receivable balance is still current and how much has slipped into the 1–30, 31–60, 61–90 and 90+ day buckets. It is a snapshot: every age is measured against one 'as of' date that you choose, usually today or a month-end. The due date each invoice is aged from comes from its payment term: check it with the invoice due date calculator.

How the math works

Age of an invoice: age = as-of date − due date, in whole calendar days.

Bucket:

  • age ≤ 0 → Current (due today or later, so not past due)
  • 1 ≤ age ≤ 30 → 1–30 days past due
  • 31 ≤ age ≤ 60 → 31–60 days past due
  • 61 ≤ age ≤ 90 → 61–90 days past due
  • age ≥ 91 → 90+ days past due (day 90 itself belongs to the previous bucket)

Bucket total: bucket total = sum of the amounts of the invoices in that bucket

Share of the balance: % of total = bucket total ÷ grand total × 100

Calendar days — weekends and public holidays are counted, and nothing is shifted to the next business day. Dates are compared at midnight UTC, so a daylight-saving change can never move an invoice by a day. Percentages are rounded to one decimal, so the five bucket shares can add up to 99.9% or 100.1% while the amounts still sum exactly to the total.

Worked example — every number below comes from the formulas above

Three open invoices, aged as of 2026-03-31:

  • 1,000.00, 2026-03-25 → age = 31 Mar − 25 Mar = 6 days → 1 ≤ 6 ≤ 30 → 1–30
  • $2,000.00, 02/10/2026 → age = 18 days left in February (28-day month in 2026) + 31 days of March = 49 days → 31 ≤ 49 ≤ 60 → 31–60
  • 3000, 2026-04-15 → age = 31 Mar − 15 Apr = −15 days → age ≤ 0 → Current

Grand total = 1,000 + 2,000 + 3,000 = 6,000.00. So the report reads:

  • Current — 1 invoice, 3,000.00 → 3,000 ÷ 6,000 × 100 = 50.0%
  • 1–30 — 1 invoice, 1,000.00 → 1,000 ÷ 6,000 × 100 = 16.7%
  • 31–60 — 1 invoice, 2,000.00 → 2,000 ÷ 6,000 × 100 = 33.3%
  • 61–90 — 0 invoices, 0.00 → 0.0%
  • 90+ — 0 invoices, 0.00 → 0.0%

Half the balance is not even due yet; a third of it is already more than a month late. Press “Load the worked example” in the form above to reproduce these exact figures — it fills in the three lines and sets the as-of date to 2026-03-31.

What we would do next in each bucket

Our own generic collection routine — not a benchmark, not a statistic, and not a substitute for your own credit policy. After you build a report, each bucket below shows how much of your balance it is holding.

  • Current

    Nothing to chase. Keep it that way: make sure every invoice leaves with an explicit due date and written terms, so the day it becomes late is never in dispute. Confirm the date with the payment due date calculator and pick your wording from invoice payment terms.

  • 1–30 days past due

    Send a short, friendly reminder that restates the invoice number, the due date it passed, the amount and how to pay. Most of what lands here is an admin gap — the invoice went to the wrong inbox, or it is waiting on a PO number. Check you sent it to the accounts-payable contact, not just your day-to-day contact.

  • 31–60 days past due

    Move off email. Call, ask directly when it will be paid, and confirm the answer in writing the same day so there is a dated commitment on record. Re-send the invoice marked past due, and re-read your own terms — if they carry a late-fee clause, this is where you tell the client it is about to apply. See invoice payment terms.

  • 61–90 days past due

    Send a final reminder with a deadline and calculate the interest your terms allow — work out the exact figure with the late fee calculator and put it on the invoice rather than leaving it as a threat. Hold new work for that client until the balance moves.

  • 90+ days past due

    Decide, and write the decision down: a payment plan you both sign, a formal demand letter, small-claims, or a hand-off to a collections agent. Whichever you pick, total the interest owed to date with the late fee calculator first, and check how long you have left under the limitation period that applies where you invoice.

Scope and limits — read before you rely on this

  • This is a bookkeeping view of a list you typed, not accounting, tax or legal advice, and not a substitute for the aging report your accounting system produces from your actual ledger.
  • It ages from the due date. If your accounting software ages from the invoice date, its buckets will be older than these by the length of your payment term.
  • It totals open balances only. Partial payments, credit notes and negative amounts are not handled — net them off before pasting, or the totals will not match your ledger.
  • No interest is added and no currency is converted. Every amount is treated as the same currency, and the symbol is display formatting only.
  • Being in an overdue bucket does not by itself make a late fee, interest or a collection cost chargeable. That depends on your contract and on the law where you invoice.
  • Everything runs in your browser. The list you paste is never uploaded, stored or sent anywhere — reloading the page clears it.