Month (Avg) to Day (mo to d)
Result
30.436875 Day
Formula
d = mo × 30.436875
1 mo = 30.436875 d, and 1 d = 0.03285488408 mo.
The second is the SI base unit, defined by a caesium-133 transition frequency. Minutes, hours, days and weeks are exact multiples. Month and year here are Gregorian averages: a year of 365.2425 days and a month of one twelfth of that (30.436875 days).
Worked examples
- 1 mo × 30.436875 = 30.436875 d
- 10 mo × 30.436875 = 304.36875 d
- 100 mo × 30.436875 = 3,043.6875 d
Common mistakes
- Calendar months run from 28 to 31 days, so "3 months" from a given date is not 3 × 30.44 days. Use a date calculator for deadlines.
- A 365-day year, a 365.25-day Julian year and the 365.2425-day Gregorian year differ; interest and astronomy calculations specify which one they use.
Month (Avg) to Day table
| Month (Avg) (mo) | Day (d) |
|---|---|
| 1 | 30.436875 |
| 2 | 60.87375 |
| 5 | 152.18437 |
| 10 | 304.36875 |
| 20 | 608.7375 |
| 50 | 1,521.8438 |
| 100 | 3,043.6875 |
| 1,000 | 30,436.875 |
The units
- Month (Avg) (mo)
- 1 Month (Avg) = 2,629,746 Second.
- Day (d)
- 1 Day = 86,400 Second.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy