They sound the same but they're not: biweekly and semi-monthly pay the same annual salary on different schedules — and that changes your paycheck size.
Biweekly = every two weeks = 26 paychecks
You're paid on a fixed day (e.g., every other Friday). 52 weeks ÷ 2 = 26 paychecks a year. Each check = annual salary ÷ 26. Two months a year you get three paychecks — which feels like a bonus.
Semi-monthly = twice a month = 24 paychecks
Paid on fixed dates (e.g., the 15th and last day). 12 months × 2 = 24 paychecks a year. Each check is slightly larger (salary ÷ 24), but you never get a "third" check month.
Same salary, different paycheck
On a $60,000 salary: biweekly ≈ $2,308/check (26×), semi-monthly ≈ $2,500/check (24×). Annual pay is identical — only the cadence and per-check amount differ.
Why it matters for budgeting
Biweekly's two "extra" months are great for savings if you budget around 24 checks. Semi-monthly lines up neatly with monthly bills. Neither pays more overall.
See your per-paycheck amount
The paycheck calculator has a per-paycheck toggle — pick your frequency to see take-home per check. Related: how to read your paycheck.