CD vs. High-Yield Savings Calculator
A CD fixes your rate; a savings account can move with the Fed. Model where savings rates head and see which one finishes ahead.
What the choice is really between
Not two rates — two guarantees. The CD guarantees the rate and gives up access; the savings account guarantees access and gives up the rate. Today’s 4.40% high-yield savings rate can be 3.40% by next summer, with no notice and no recourse. A 4.40% CD cannot. Every dollar you hold should be assigned to whichever guarantee it genuinely needs.
The drift slider above is the entire decision. Set it to whatever you believe the Fed will do. At −0.75 points a year — roughly what markets price today — a 24-month CD beats savings by a couple of hundred dollars per $25,000. If you set drift to zero and savings still loses, the CD is simply the better deal outright.
The split most savers should actually make
The standard answer is boring and correct: emergency fund in savings, everything with a date on it in CDs. Three to six months of expenses stays liquid, because its job is availability rather than yield. Money for a 2028 tuition bill has no business earning a variable rate when a fixed one is available. The interesting margin is the money in between, and that is what ladders are for.