How to Convert Weeks to Days and Hours — Time Conversion Reference

A project deadline set in weeks, a medication course measured in weeks, a sprint duration, a lease notice period — all of these eventually need to translate to a concrete number of days or hours. The math is straightforward, but having a reference table saves recalculation every time.

Use the Time Converter to convert any time value across all units instantly. This article covers week-to-day and week-to-hour conversions with full reference tables and practical applications.

The Exact Conversion

1 week = 7 days (exact, by definition) 1 week = 168 hours (7 × 24) 1 week = 10,080 minutes (168 × 60) 1 week = 604,800 seconds (10,080 × 60)

These are clean, exact numbers with no approximation. Unlike month and year conversions — which require accounting for variable month lengths and leap years — week conversions are always precise.

Weeks to Days Reference Table

Note: 52 weeks = 364 days, which is one day short of a standard 365-day year. A calendar year has 52 weeks plus 1 day (or 2 days in a leap year). This is why annual planning in exact weeks sometimes uses 52 or 53 ISO weeks depending on the year.

Weeks vs Months: When They're Not the Same

Four weeks is not the same as one month. This is a common source of confusion:

• 4 weeks = exactly 28 days
• 1 month = 28, 29, 30, or 31 days depending on the month

For months with 30 or 31 days, a 4-week period is 2–3 days short of a calendar month. Over a year, this adds up:

• 12 months = 365 or 366 days
• 48 weeks (12 × 4) = 336 days — nearly a month shorter

When a contract says "4 weeks notice," it means exactly 28 days. When it says "1 month notice," it means the same calendar date in the following month (e.g., notice given March 15 expires April 15). These are different durations, and confusing them can create legal issues.

Similarly, "bi-weekly" is genuinely ambiguous — it can mean "every two weeks" (14 days) or "twice a week" (3–4 days). In professional and contractual contexts, specify "every two weeks" or "twice per week" rather than "bi-weekly" to avoid this ambiguity.

Practical Applications by Industry

Project Management and Sprints

Agile sprints are typically 1 or 2 weeks. In hours:

• 1-week sprint = 168 calendar hours = ~40 working hours (5 days × 8 hours)
• 2-week sprint = 336 calendar hours = ~80 working hours

When planning sprint capacity, the relevant figure is working hours, not total hours. A 2-week sprint with 5 team members at 40 hours each = 200 person-hours of capacity (before subtracting time for meetings, reviews, and other overhead).

For milestone planning, 13 weeks = one quarter (91 days). Four quarters × 13 weeks = 52 weeks, which aligns closely with a calendar year.

Medical and Health Timelines

Medical durations are frequently expressed in weeks:

• Pregnancy: 40 weeks = 280 days from last menstrual period
• Antibiotic courses: 1–2 weeks (7–14 days)
• Post-surgery recovery: often 6–12 weeks (42–84 days)
• Physical therapy programs: commonly 8–12 weeks (56–84 days)

Weeks are used in medicine because they correspond naturally to follow-up appointment scheduling (weekly or biweekly) and to biological timelines that don't align with calendar months.

Pregnancy in weeks vs months: Pregnancy is measured in weeks by healthcare providers but described in months by most people conversationally. The conversion is approximate:

• 4 weeks ≈ 1 month
• 8 weeks ≈ 2 months
• 12 weeks = end of first trimester (3 months)
• 28 weeks = end of second trimester (7 months)
• 40 weeks = full term (10 months by 4-week counting, or 9 calendar months)

Payroll and Employment

Bi-weekly payroll (every 2 weeks) produces 26 pay periods per year. Semi-monthly payroll (twice per calendar month) produces 24 pay periods per year. The difference matters for annualizing pay:

• Bi-weekly: annual salary ÷ 26 = gross pay per period
• Semi-monthly: annual salary ÷ 24 = gross pay per period

A $78,000 annual salary pays $3,000 per period bi-weekly and $3,250 per period semi-monthly — the per-period amount is different even though the annual total is identical.

Notice periods and probation periods are often stated in weeks in employment contracts. A 4-week notice period starting Monday April 7 ends Sunday May 4 (28 days later). If the contract says "one month," it ends May 7 — a difference of 3 days.

Shipping and Logistics

Lead times in manufacturing and logistics are often expressed in weeks:

• 2-week lead time = 14 calendar days
• 6-week lead time = 42 calendar days
• 12-week lead time = 84 calendar days

When a supplier quotes "8–10 weeks," that's 56–70 calendar days. Converting to days helps when calculating back-dates from a project deadline.

Example: Product launch is June 30. Supplier needs 10 weeks lead time. Order must be placed by: June 30 − 70 days = April 21.

Fitness and Training Programs

Training blocks in sport and fitness are almost always structured in weeks:

• 4-week mesocycle (a common training block)
• 8-week beginner program
• 16-week marathon training plan
• 52-week annual training plan

In hours of training per week, these convert to total training volume:

• 8-week program at 5 hours/week = 40 total training hours
• 16-week marathon plan at 8 hours/week = 128 total training hours

Working Hours vs Total Hours in a Week

A week has 168 hours total. Standard full-time employment uses 40 of those hours for work — about 24% of the week.

The 56.5 discretionary hours includes evenings, weekends, and other non-committed time. This is a rough average — actual distribution varies significantly based on commute, family responsibilities, and working hours.

Converting Partial Weeks

For fractional weeks, multiply by 7 for days, then by 24 for hours:

• 1.5 weeks = 1.5 × 7 = 10.5 days = 252 hours
• 2.5 weeks = 2.5 × 7 = 17.5 days = 420 hours
• 0.25 weeks = 0.25 × 7 = 1.75 days = 42 hours

The Time Converter handles any decimal input, so you can convert 2.75 weeks or 0.3 weeks directly without manual calculation.