CMT vs SOFR ARM 2027 Comparison Calculator

CMT (Constant Maturity Treasury, 1-year) vs SOFR (Secured Overnight Financing Rate). SOFR replaced LIBOR in 2023 for new ARMs. CMT slightly more volatile, slightly higher yield. SOFR cleaner + transparent. Margin typically 2-3 percentage points added to index = your rate.

ARM loan amount ($)

Current 1Y CMT (%)

Current SOFR (%)

Margin (%)

LIBOR Sunset

LIBOR retired June 2023. New ARMs use SOFR or CMT. Existing LIBOR loans transitioned via Fallback Provisions Act.

SOFR Mechanics

Secured Overnight Financing Rate. Treasury repo market benchmark. Daily published by NY Fed. 30-day average smoothed for ARM.

CMT Mechanics

Constant Maturity Treasury 1-year. Daily Treasury yield curve interpolation. Slightly more volatile than SOFR.

Source and Disclaimer

Federal Reserve, NY Fed SOFR. Rates as of May 2026 — refresh daily.

Source: federalreserve.gov, newyorkfed.org SOFR. Last updated: May 2026.