Day to Year (Avg) (d to yr)
Result
0.002737907007 Year (Avg)
Formula
yr = d × 0.002737907007
1 d = 0.002737907007 yr, and 1 yr = 365.2425 d.
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 d × 0.002737907007 = 0.002737907 yr
- 10 d × 0.002737907007 = 0.02737907 yr
- 100 d × 0.002737907007 = 0.2737907 yr
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.
Day to Year (Avg) table
| Day (d) | Year (Avg) (yr) |
|---|---|
| 1 | 0.002737907 |
| 2 | 0.005475814 |
| 5 | 0.013689535 |
| 10 | 0.02737907 |
| 20 | 0.05475814 |
| 50 | 0.13689535 |
| 100 | 0.2737907 |
| 1,000 | 2.737907 |
The units
- Day (d)
- 1 Day = 86,400 Second.
- Year (Avg) (yr)
- 1 Year (Avg) = 31,556,952 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