Months Calculator

The Months Calculator helps you quickly calculate how many months fall between two dates, or what date it will be if you add or subtract a number of months from a starting point. Whether you’re planning future milestones, backdating events, or just checking date spans, this tool makes it simple and accurate.

You can switch between three useful modes Add Months, Subtract Months, or Months Between and the tool adjusts its inputs accordingly. You’ll also get expanded features like the ability to skip end-of-month rollover issues, show the day of the week, and even treat months as fixed 30-day blocks when needed. It’s built for flexibility, and the results update live with a quick flash so you always know they’re fresh.

Options
Use verbose output
Include start date
Adjust day rollover
Treat months as 30 days

How to Use:

  1. Choose a Mode:
    • Months Between: Calculates how many calendar months and total days fall between two dates.
    • Add Months: Moves forward from a date by a set number of months.
    • Subtract Months: Moves backward instead.
  2. Fill in the Dates:
    • Start Date is always required.
    • End Date only appears in Months Between mode.
    • Month count field appears for Add/Subtract modes.
  3. Toggles:
    • Use verbose output shows dates like “Monday, June 15, 2025.”
    • Include start date counts the first date in the result.
    • Adjust day rollover prevents invalid date overflow (e.g. Jan 31 → Feb 28).
    • Treat months as 30 days useful for financial-style month calculations.
  4. Click Calculate or just start typing the result updates live.
  5. Copy, Export, or Reset as needed.

What Months Calculator can do:

It gives you months between dates, calculates future or past months from a given date, and accounts for real-world variations in month lengths and weekends. It even shows total day counts and the resulting day of the week giving you a more complete answer than a basic date calculator.

Example:

Mode: Add Months
Start Date: 2025-01-31
Months to Add: 1
Adjust rollover: On
Verbose Output: On

Output:

Start: Friday, January 31, 2025
Months added: 1
Result Date: Friday, February 28, 2025

Common Use Cases:

Use the Months Calculator to calculate subscription terms, payment schedules, leave durations, or project phases. Whether you’re adding months, backdating a task, or measuring gaps in time this tool adapts to your needs and gives a complete, human-readable result.

Useful Tools & Suggestions:

If you’re checking the space between two months, the Date Duration Calculator works great when you want total days too not just months. And for a quick jump forward or back, the Add Time Calculator makes it easy to shift by months, days, or anything in between.

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