What is the difference between biweekly and semi-monthly pay?

Biweekly means every two weeks on the same weekday, which adds up to 26 (sometimes 27) paychecks a year and creates 3-paycheck months. Semi-monthly means twice a month on fixed dates such as the 1st and 15th, which is always exactly 24 paychecks and never produces an extra one.

Is my payday information sent anywhere?

No. The calculator and the calendar file are generated entirely in your browser. Nothing you type is uploaded or stored.

3 Paycheck Months Calculator

Enter any one of your paydays and see every month with an extra paycheck from 2026 through 2030 — plus whether your year has 27 paydays.

By bughatti · Updated September 26, 2026 · Runs in your browser; nothing you type is uploaded.

How the calculator works

Biweekly pay means a paycheck every 14 days on the same weekday. A year is 365 days (366 in a leap year), which is 26 two-week periods plus one or two days left over. Most months have room for two paydays, but because 26 paydays have to fit into 12 months, two months every year get a third paycheck. Weekly pay works the same way: 52 or 53 paydays spread over 12 months means four or five months get a fifth paycheck.

The calculator steps forward and backward from the payday you enter in exact 14-day (or 7-day) jumps, groups the dates by month, and highlights every month that ends up with more paychecks than usual. The leftover days also add up: roughly once every 11 years a biweekly schedule fits 27 paydays into one calendar year, and weekly schedules hit 53 paydays about every 5 to 6 years.

Worked example: 2027

Two people, both paid every other Friday, one week apart:

First payday of 2027	Paychecks in 2027	3-paycheck months
Friday, January 1	27	January (1, 15, 29), July (2, 16, 30), December (3, 17, 31)
Friday, January 8	26	April (2, 16, 30), October (1, 15, 29)

Same employer, same pay, one week apart — and one of them gets an entire extra paycheck in 2027. That is why it pays to check your own dates instead of relying on a generic list. Paid weekly on Fridays in 2027, you would get 53 paychecks, with five-paycheck months in January, April, July, October and December.

What to do with a 3-paycheck month

The mistake most people make is treating the third paycheck like the other two. If your fixed bills are already covered by two paychecks a month, the third one is money you did not need for rent, utilities or car payments that month. A plan made in advance keeps it from disappearing into everyday spending:

Refill your cushion first. If your checking account ran low in a tight month, top it back up so the next surprise bill doesn't end up on a credit card.
Pay down the most expensive debt. One extra paycheck toward a high-interest card can save more than it looks like, because it cuts the balance that interest is charged on.
Pre-fund a sinking fund. Car registration, holidays, annual subscriptions — the bills that come once a year are easier when a whole extra paycheck goes straight into their pot.
Pay a bill a month early. Covering next month's rent or insurance from the extra check gives you breathing room in the following, two-paycheck month.

Why budgeting by paycheck matters here: if you budget by month, the third paycheck just looks like "a good month." If you budget each paycheck on its own — deciding what that one check pays for before you spend it — the extra paycheck shows up as exactly what it is: money with no bill attached yet. That is the idea behind Paychunk, which splits each paycheck into what you can spend per day, week and month, without linking your bank. See how Paychunk budgets by paycheck →

Biweekly vs. semi-monthly: which one are you?

Look at your last few pay stubs. If the dates move around the calendar but always fall on the same weekday (every other Friday, for example), you are paid biweekly and you will get 3-paycheck months. If you are paid on the same dates every month, such as the 1st and 15th or the 15th and last day, you are paid semi-monthly: always 24 paychecks a year, and never a third one in a month. Semi-monthly paychecks are slightly larger to make up for it.

Frequently asked questions

How many 3-paycheck months are there in a year?

With biweekly pay, two in most years. In a 27-paycheck year, three.

Does 2027 have 27 paychecks?

For some schedules, yes. Paid every other Friday starting January 1, 2027, you get 27 (the last on December 31). A schedule that started on January 8 gets the usual 26. Enter your own payday above to check yours.

My employer pays on the last business day of the month. Does this apply?

No — that is a monthly (or semi-monthly) schedule tied to calendar dates, so every month has the same number of paychecks.

Is my information sent anywhere?

No. Everything is calculated in your browser, and the calendar file is created on your device. Paychunk doesn't see what you type.