# GOOGLEFINANCE vs a Currency Add-On: When a Formula Is Enough

> Three ways to convert currency in Google Workspace – the free formula, your own script, an add-on – and an honest decision table for which fits which job.

- Source: https://www.8apps.co/blog/googlefinance-vs-currency-addon
- Markdown: https://www.8apps.co/blog/googlefinance-vs-currency-addon.md
- Published: 2026-09-16
- Author: 8apps Team
- Language: en

---
## The honest opening: the formula is often enough

If your whole need is a live rate in a spreadsheet cell, stop reading and type `=GOOGLEFINANCE("CURRENCY:USDEUR")`. Free, instant, no install. This page exists for the jobs where that stops being true – and it is specific about where the line sits.

## Route 1 – GOOGLEFINANCE: free, capable, bounded

What it does well: live rates (*"delayed by up to 20 minutes"*, per Google's help page), historical rate-on-a-date via the `INDEX(...)` unwrap, all inside the sheet with zero setup.

Its documented boundaries, which are the actual decision inputs: it exists **only in Sheets** – Docs, Gmail, Slides and Calendar have no formula engine, so it cannot follow you there; historical data *"cannot be downloaded or accessed via the Sheets API or Apps Script"* – no automation may read it; Google *"cannot guarantee the accuracy of the exchange rates displayed"* and tells you to confirm current rates before any transaction they could affect; and the `CURRENCY:` syntax it all rests on is absent from Google's own documentation – working but unpromised. The [troubleshooting guide](/blog/googlefinance-exchange-rate-not-working) has every documented failure mode.

## Route 2 – your own script: control, for a price

Apps Script calling a real rate API (the ECB's free daily reference feed, or a commercial provider) gets you what GOOGLEFINANCE refuses: automatable rates, your choice of source, your refresh schedule. The price is the build and the care: API keys, a custom function that *"must return within 30 seconds"* or the cell shows `#ERROR!`, a daily URL Fetch quota (20,000 calls a day on a consumer account, 100,000 on Workspace), and maintenance forever. Right when rates feed a *system*; overkill when they feed a human.

## Route 3 – an add-on: for the jobs that aren't in a cell

The case for an add-on is mostly about *where* conversion needs to happen and *who* is doing it: a quote being written in Docs, an invoice being checked in Gmail, a colleague who should not need formula syntax to answer "what's that in euros". A sidebar that converts on the spot, across the apps where the work already is, is a different tool from a formula – not a better formula.

## The decision table

| Job | Use |
|---|---|
| Live rate in a sheet cell | **GOOGLEFINANCE** |
| Rate-on-a-date for an invoice column | **GOOGLEFINANCE**, then paste-values |
| Rates feeding a script or pipeline | **Your own script + a rate API** (GOOGLEFINANCE is blocked here) |
| Converting while writing a Doc, email or slide | **Add-on** – no formula engine exists there |
| Colleagues converting ad hoc, no syntax | **Add-on** |
| Audit-grade or trading-grade rates | **None of these** – Google says to confirm rates before transactions; use an official source such as a central bank |

## Where Currency Converter fits

[Currency Converter](/google-workspace/currency-converter) is route three: a sidebar converting 180+ currencies at live rates inside Gmail, Docs, Calendar, Slides and Sheets. Sidebar conversions are unlimited and free with no sign-up; a Premium tier adds a Sheets formula with historical rates back to 2000. So the honest advice stands: use the formula where the formula works, and the sidebar where it can't follow.

## Sources

- [GOOGLEFINANCE – Google Docs Editors Help](https://support.google.com/docs/answer/3093281) – read 2026-09-16
- [Google Finance disclaimer](https://www.google.com/googlefinance/disclaimer/) – read 2026-09-16
- [ECB euro foreign exchange reference rates](https://www.ecb.europa.eu/stats/policy_and_exchange_rates/euro_reference_exchange_rates/html/index.en.html) – read 2026-09-16
- [Apps Script – Custom functions](https://developers.google.com/apps-script/guides/sheets/functions) and [Quotas for Google Services](https://developers.google.com/apps-script/guides/services/quotas) – read 2026-09-16
- [Currency Converter by 8apps](/google-workspace/currency-converter) – product claims, read 2026-09-16