Months Between Dates Calculator
Count the full months — and the days left over — between two dates.
Dates use your device’s calendar. Business days are Monday to Friday.
How months are counted
A month is counted from one day to the same day of the next month: 15 January to 15 April is 3 months. If the end date is earlier in the month, the remaining days are shown separately: 15 January to 10 April is 2 months and 26 days.
The decimal result divides the days left over by the average month length of 30.44 days.
Months for contracts and age
Lease terms, probation periods and a baby’s age are usually given in months. For the exact age in years, months and days, the main days between dates calculator shows the full breakdown.
Frequently asked questions
How do I calculate the months between two dates?
Count the full months from the start day to the same day in later months, then add the days left over.
How many months is 90 days?
About 2.96 months on average — 2 months and around 29 to 31 days, depending on the months.
What if the start date is the 31st?
In shorter months the calculator uses the last day of the month, so 31 January plus one month is 28 or 29 February.