SARON Calculator
Compound official daily SARON fixings over your exact interest period, add your margin and get the interest amount in francs. Built for CHF facility agreements and SARON mortgages alike. Free, with no publication delay and no 12 month limit. The latest SARON fixing is -0.060% as of .
Want to automate these calculations? Use our API
Beyond the realised rate
See where SARON is heading next
- Market-implied SARON forward curve
- Full daily compounded history
- Excel Add-in & API access
- Price CHF swaps and caps
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“I do debt service forecasting for any of the facilities where we have floating rate exposure… I like this option to just pull the forward curve monthly or quarterly going out.”
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That's what the last period cost. See what the next one is likely to.
Compounded SARON tells you what an interest period has already cost. The SARON forward curve implies the path of future fixings straight from today's CHF swap pricing, so you can budget the next reset before it lands.
See the SARON forward curveThis calculator in Excel & API
If you're running this calculation more than once a month, you don't need a calculator, you need a feed. The compounding on this page is one API call, and the published compounded series drop straight into Excel.
// Excel: any day's compounded SARON in a cell =BlueGamma.FIXING("3M COMPOUNDED SARON", accrual_date) # API: this exact calculation, one GET away GET api.bluegamma.io/v1/compounded_rate ?index=SARON&start_date=YYYY-MM-DD &end_date=YYYY-MM-DD&lookback_days=5 x-api-key: your_api_key
FAQs
The calculator compounds each daily SARON fixing in arrears across your start and end dates on an Actual/360 basis with the Zurich business day calendar, following the standard formula recommended by the National Working Group on Swiss Franc Reference Rates. Non-business days carry the previous fixing. Because every fixing in the window is already published, the result is the realised rate for the period, not a forecast. SIX administers SARON and publishes it every Zurich business day; it replaced CHF LIBOR as the Swiss franc reference rate.
Both compound the same official fixings. The SIX calculator is free for non-professional use, has a built-in delay of three business days and covers date combinations within the last 12 months. This one is free for professional use too, runs on the latest published fixing with no delay, works across the full fixing history, and adds a margin input and the interest amount in francs.
Yes. SARON tracks the Swiss National Bank policy rate closely and has spent long stretches below zero; in mid 2026 the compounded rate is slightly negative again. On a SARON mortgage the margin is added on top, and many contracts floor the reference rate at zero, so check your agreement before applying a negative rate to your balance.
Enter your interest period start and end dates, your outstanding balance as the nominal amount, and your contractual margin in the margin field. The calculator returns the all-in rate and the interest amount for the period, which you can compare against your bank statement.
Worked example: a CHF 1,000,000 SARON mortgage with a 90bp margin for the quarter from 1 April to 30 June 2026, compounding on an Actual/360 basis. Compounded SARON for the period is negative, at −0.04221%; adding the margin gives an all-in rate of 0.85779% and interest of CHF 2,144.48. Note the negative reference rate: many Swiss contracts floor SARON at zero, which would make the all-in rate the full 0.90% margin. Daily compounded SARON history is on our compounded SARON page.
More on SARON rates
SARON fixings
Todays SARON rate and the daily official fixing history.
Compounded SARON rates
Daily 1M, 3M, 6M and 12M compounded SARON values.
SARON forward curve
Where the market prices SARON from here, updated live.
CHF swap rates
Live SARON swap rates across the tenor grid.
RFR calculator
The same tool across SOFR, SONIA, €STR, ZARONIA and more.
Other calculators
Or browse all seven on the calculators page.