14 July 2026 · Risk Free Rates Team
SOFR vs Prime Rate: What's the Difference and Which Applies to Your Loan?
SOFR and the Prime Rate are both widely used loan benchmarks, but they're built completely differently and sit at very different levels. Here's how each works and which one actually shows up in your loan.
Two Very Different Benchmarks
If you've shopped for a loan recently, you've probably seen your rate quoted against one of two very different reference points: SOFR or the Prime Rate. Both are "benchmark" interest rates that borrowers' loan pricing floats against, but they're constructed in almost opposite ways.
SOFR is a transaction-based rate — the Federal Reserve Bank of New York calculates it every business day from actual overnight Treasury repo trades. More than $1 trillion changes hands in that market daily, so SOFR reflects real, observed borrowing costs.
The Prime Rate, by contrast, is a survey-based, administratively set rate. The most widely quoted version — the Wall Street Journal Prime Rate — is compiled by surveying the prime lending rate posted by most of the 10 largest U.S. banks. It isn't derived from any single day's trading activity; it's simply what large banks say they charge their most creditworthy customers, and in practice it moves in lockstep with Federal Reserve policy rather than daily market conditions.
How the Prime Rate Is Set
The mechanical relationship is simple and well-established: the WSJ Prime Rate has, for decades, tracked the federal funds rate's upper target bound plus 3 percentage points. When the Federal Open Market Committee changes its target range, the largest banks adjust their posted prime rate the same day, and the WSJ survey reflects that new level.
As of July 2026, the FOMC's target range has been held at 3.50%–3.75% through several consecutive meetings this year, and the WSJ Prime Rate has correspondingly sat at 6.75%, unchanged for the past several months and down from 7.50% a year earlier when the target range was higher. The Federal Reserve's discount rate — a related but separate benchmark for direct bank borrowing from the Fed — has stood at 3.75% over the same period, according to Bankrate's tracked rate data.
Because Prime only moves when the Fed acts (or, less commonly, when banks independently adjust), it changes in discrete steps a handful of times a year at most — nothing like the daily fluctuation you see with SOFR.
SOFR vs Prime Rate: Key Differences
| Feature | SOFR | Prime Rate |
|---|---|---|
| Basis | Actual overnight Treasury repo transactions | Survey of large banks' posted lending rate |
| Administrator | Federal Reserve Bank of New York | The Wall Street Journal (informal survey) |
| Update frequency | Daily | Only when the Fed changes its target range (a few times a year at most) |
| Typical level | Tracks close to the effective fed funds rate | Fed funds upper bound + ~3 percentage points |
| Common uses | Syndicated/commercial loans, derivatives, floating-rate notes | Small business loans, HELOCs, credit cards, personal loans, some consumer ARMs |
| Day-to-day volatility | Can spike around quarter-end repo market stress | Essentially flat between Fed decisions |
Which One Applies to Your Loan?
Which benchmark you'll actually see depends heavily on the type of borrower and loan:
- Large syndicated and commercial credit facilities overwhelmingly use SOFR today — either Compounded SOFR in Arrears or Term SOFR, per the market conventions recommended by the Alternative Reference Rates Committee (ARRC) during the LIBOR transition.
- Small business loans, home equity lines of credit (HELOCs), credit cards, and many personal loans still commonly reference the Prime Rate. Unlike SOFR, Prime was never part of the LIBOR replacement effort — it predates that transition entirely and has its own long-standing role in consumer and small-business lending.
It's not unusual for a single borrower to hold both kinds of debt at once — a SOFR-based term loan on the business's main credit facility, say, alongside a Prime-based business line of credit or HELOC — so understanding both benchmarks matters even if only one shows up on any individual loan.
Why the Spread Between Them Matters
Because Prime is mechanically pinned at roughly fed funds + 3%, and SOFR tracks close to the fed funds effective rate, the gap between the two benchmarks is normally fairly stable — around 3 percentage points, give or take. That means a "SOFR + 2.50%" loan and a "Prime + 0.00%" loan can end up costing a borrower very similar amounts, even though the headline numbers look nothing alike.
The one wrinkle: SOFR is a market rate, not an administered one, so it can temporarily spike around quarter-end dates or other periods of repo market stress — something that structurally can't happen to Prime, which only moves when the Fed decides to move it. If you're comparing quotes across the two benchmarks, it's worth checking whether the SOFR side of the comparison reflects a smoothed, compounded average rather than a single volatile day's print.
Frequently Asked Questions
What is the Prime Rate? The Prime Rate — most commonly the Wall Street Journal Prime Rate — is a benchmark interest rate based on a survey of what the largest U.S. banks charge their most creditworthy customers. It tracks the Federal Reserve's target federal funds rate plus roughly 3 percentage points.
Is the Prime Rate the same as SOFR? No. SOFR is a daily, transaction-based rate derived from actual Treasury repo trades and administered by the New York Fed. Prime is a survey-based rate that only changes when the Fed adjusts its policy rate, and it sits structurally higher than SOFR — currently around 6.75% versus SOFR's roughly 3.5% level.
Why is the Prime Rate higher than SOFR? By convention, the WSJ Prime Rate equals the top of the Fed's target federal funds range plus about 3 percentage points, while SOFR tracks close to the fed funds rate itself. That built-in margin is why Prime consistently runs several points above SOFR.
Does the Prime Rate change every day like SOFR? No. SOFR is published fresh every business day. The Prime Rate only changes when the Federal Reserve moves its target rate (or, rarely, when banks adjust independently of the Fed) — typically a handful of times per year at most.
Compare Both Sides of a Loan
Our free RFR Loan Calculator calculates compounded-in-arrears or Term SOFR interest with a full daily rate ledger — useful for lining up the SOFR side of a loan comparison against a Prime-based quote from your lender.