In 1 years there are 52.142857 weeks. Meanwhile in 1 weeks there are 0.019178 years. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Weeks to Years calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert years to weeks, multiply the number of years by the number of weeks in a year.
Standard (non-leap) year: 1 year = 52 weeks + 1 day (365 days)
Leap year: 1 year = 52 weeks + 2 days (366 days)
Fast estimate for everyday use:
More accurate average across many years:
Tip: A week is 7 days, so you can always convert by using days ÷ 7 if you start from days.
A common year has 365 days, which equals 52.1429 weeks (365 ÷ 7). That’s 52 weeks plus 1 extra day. In everyday use, people often say “52 weeks in a year.”
A leap year has 366 days. That equals 52.2857 weeks (366 ÷ 7). It’s 52 weeks plus 2 extra days.
A week is always 7 days, but a year is 365 or 366 days. Since 52 weeks is 364 days, there are leftover days each year. Those leftover days are why the numbers don’t match exactly.
Multiply years by 52.1429 to get an average result. This uses the average year length of 365 days. For exact results, choose 365 days (common year) or 366 days (leap year), then divide by 7.
Use actual dates. Count the total days between the start date and end date, then divide by 7. This method handles leap years and date ranges that cross calendar years.
It works for rough estimates, schedules, and simple planning. It undercounts by about 1 to 2 days each year. Over many years, that gap adds up.
Using an average year: 2 × 52.1429 = 104.2858 weeks. Using common years only: 730 ÷ 7 = 104.2857 weeks. The result is about 104.29 weeks.
Using an average year: 5 × 52.1429 = 260.7145 weeks. The exact value depends on how many leap years fall in that 5-year span.
Using an average year: 10 × 52.1429 = 521.429 weeks. For exact totals, count the number of leap years in the 10-year period.
Using an average year: 20 × 52.1429 = 1,042.858 weeks. The exact total changes slightly based on how many leap years occur.
Half a year is about 0.5 × 52.1429 = 26.0714 weeks. In days, half of a 365-day year is 182.5 days, which is 26.0714 weeks.
1.5 years is about 1.5 × 52.1429 = 78.2143 weeks. This is useful for project timelines and plan lengths.
If you treat 6 months as half a year, it’s the same as 1.5 years. That’s about 78.2143 weeks. If you use exact calendar months, the total depends on which months you mean.
Divide weeks by 52.1429 to get years, using an average year. For example, 104 weeks ÷ 52.1429 ≈ 1.9945 years. For exact date-based results, convert weeks to days (weeks × 7) and map to real dates.
In day counts, a year never has 53 full weeks because 53 weeks is 371 days. Some calendar systems and work-week numbering can label a year as having “week 53,” but the year still has 365 or 366 days.
Many payroll plans use 52 weeks as a base. Some jobs plan around 26 biweekly pay periods (52 weeks). Real calendars can create an extra day (or two in leap years), which can affect pay dates and schedules.
The exact weeks per year depends on whether it’s a common year or a leap year. Common year: 52.1429 weeks. Leap year: 52.2857 weeks. The average across many years stays close to 52.1775 weeks because leap years happen on a set rule.
For long spans, the average year works well for estimates: 52.1429 weeks per year (based on 365 days). If you need precision for legal, medical, or finance use, count days between dates and divide by 7.
The Calculate Box tool to convert years to weeks uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a years value in the box and have it instantly converted to weeks.