Convert Weeks to Days – Time Converter
This converter converts a numeric value in weeks to the equivalent number of days using the standard fixed relationship between these units. It is intended for scheduling, planning, data normalization, and quick unit-check calculations.
The mathematical conversion is exact in the sense that one week equals seven days. Use the guidance below when converting fractional weeks, when mapping durations onto calendar dates, or when work-week/business-week conventions matter.
Interactive Converter
Convert between week and day with precision rounding.
Quick reference table
| Week | Day |
|---|---|
| 1 wk | 7 d |
| 5 wk | 35 d |
| 10 wk | 70 d |
| 25 wk | 175 d |
| 50 wk | 350 d |
| 100 wk | 700 d |
Methodology
The conversion uses the fixed, definition-level relationship that one week equals seven days. For pure duration arithmetic (for example, converting a duration measured in weeks into a duration measured in days), multiply the numeric week value by 7.
For calendar calculations that map a week count onto specific dates, consider calendar rules such as ISO week numbering (ISO 8601) and local week-start conventions; those rules affect date alignment but do not change the weeks-to-days multiplication.
Where traceability, measurement uncertainty, or timestamp synchronization matter, follow time and measurement guidance from authoritative bodies. See NIST for time and frequency references, ISO 8601 for week/date formats, IEEE standards for precise timing and synchronization, and applicable occupational rules for work-week definitions.
Worked examples
2 weeks → 14 days
0.5 weeks → 3.5 days
52 weeks → 364 days
Further resources
External guidance
Expert Q&A
Is one week always seven days?
Yes. In standard civil and scientific unit definitions used for duration arithmetic, one week is defined as seven days. Week numbering systems and work-week definitions do not alter this fixed multiplicative relationship.
How should I handle fractional weeks?
Multiply the fractional week value by 7. For user-facing output, round to the number of decimal places appropriate for your context (for example, hours or days).
Does daylight saving time or leap seconds affect this conversion?
No for unit conversion: one week equals seven days as a unit relationship. However, when converting between calendar dates or clock times (for example, adding a week to a timestamp), daylight saving time shifts and leap seconds affect clock times and may require time-zone-aware date arithmetic.
What is the difference between a calendar week and a business week?
A calendar week is any seven-day period and is commonly aligned with ISO or local definitions of week start. A business week typically refers to working days within that week (commonly Monday–Friday) and is a counting convention that excludes weekends; converting between weeks and business days requires applying the business-day rule, not just multiplying by seven.
How precise is this conversion?
The mathematical conversion is exact. Practical precision depends on input precision and how you choose to round the output. For high-precision timing or regulatory compliance, follow guidance from standards bodies cited below and document rounding rules.
Sources & citations
- NIST Time and Frequency Division overview — https://www.nist.gov/pml/time-and-frequency-division
- ISO 8601 - Date and time format — https://www.iso.org/iso-8601-date-and-time-format.html
- IEEE standards overview (time and synchronization) — https://standards.ieee.org/
- OSHA - Occupational safety and health administration — https://www.osha.gov