Live exchange rates in Excel with Power Query

The cleanest way to get live exchange rates into Excel is a Power Query M query that calls /v1/latest/USD and loads the rates onto a worksheet. It refreshes on workbook open or a manual click, runs the same on Mac and Windows, and needs no add-in. A free key covers 10,000 calls a month. This is the live-data feed an FX-linked financial model wants — DCF inputs, hedging sheets, a multi-currency P&L that updates when you open it.

Get a free API key

Sign up at exchangerate.dev/signup. After email confirmation your dashboard shows a key starting with exr_live_. Copy it — you will paste it into the query as a parameter. The free tier is 10,000 calls a month, no card required.

Open the Power Query editor

From the Excel ribbon, click Data → Get Data → Launch Power Query Editor. Inside the editor, click Home → New Source → Blank Query, then View → Advanced Editor. You will paste the M query into that box in the next step.

Paste the M query

Replace the editor contents with the query below and click Done, then rename the query FxRates in the right rail. The RelativePath argument is not optional — without it, scheduled refresh in Microsoft 365 fails with a credentials error.

// excel: Power Query M query "FxRates"
// curl-equivalent: https://api.exchangerate.dev/v1/latest/USD
// Replace ApiKey with your exchangerate.dev key from /signup
let
    ApiKey = "exr_live_replace_with_your_key_here",
    Base = "USD",
    Source = Json.Document(
        Web.Contents(
            "https://api.exchangerate.dev",
            [
                RelativePath = "v1/latest/" & Base,
                Headers = [#"Authorization" = "Bearer " & ApiKey]
            ]
        )
    ),
    Rates = Record.ToTable(Source[rates]),
    Renamed = Table.RenameColumns(Rates, {{"Name", "currency"}, {"Value", "rate"}})
in
    Renamed

Load to a worksheet, choose Anonymous

Click Home → Close & Load. Excel drops a two-column table — currency and rate — onto a new sheet. On first run Excel asks how to authenticate the https://api.exchangerate.dev source: choose Anonymous. Your key travels in the header, not the URL, so Anonymous is correct. Press Ctrl+Alt+F5 any time to refresh.

Switch the base or filter to a few pairs

Change the Base to re-base every rate, or add a symbols query to return only the pairs you need — fewer rows, same single call:

// Re-base every rate to the euro
Base = "EUR"

// Return only the quote currencies you need (one call, fewer rows)
RelativePath = "v1/latest/USD",
Query = [symbols = "EUR,GBP,JPY"]

// One pair, rate calculated for you
RelativePath = "v1/convert/USD/JPY/1"   // read Source[rate]

Refresh and free-tier fit

Excel does not poll on its own. The table refreshes when you open the workbook, click Refresh All, or set a periodic refresh under Data → Queries & Connections → Properties. The math stays well inside the free tier:

• 10,000 calls a month, 12 requests a minute, no card
• A typical model fires a handful of calls a day (open + a few manual refreshes)
• Even a 5-minute auto-refresh during market hours lands near 100 calls a day
• Covers /v1/latest, /v1/convert, /v1/range, and /v1/{date}/{base}