Time converter: seconds, minutes, hours, days, weeks, and years

Convert between seconds, minutes, hours, days, weeks, months, and years at ToolHQ's time converter, with an accurate reference table including the exact number of seconds in a year. Free, no account required.

Time units are straightforward in concept but get confusing at larger scales. How many hours are in a year? How many seconds in a month? How many weeks in a decade? These questions come up in project planning, software development (uptime SLAs), science, and everyday scheduling. The answers depend on which definition of "year" and "month" you use.

ToolHQ's time converter handles seconds through years with accurate conversion factors and returns all equivalents simultaneously.

Key Takeaways

• 1 year = 365.25 days = 8,766 hours = 525,960 minutes = 31,557,600 seconds
• 1 day = 24 hours = 1,440 minutes = 86,400 seconds
• 1 week = 7 days = 168 hours = 10,080 minutes = 604,800 seconds
• Month conversion is approximate: 1 month = 30.44 days = 730.5 hours (varies by calendar month)
• No data is stored or transmitted, all calculations run locally in your browser

---

Time unit conversion table

The standard conversion chain from seconds up to years:

Unit	Seconds	Minutes	Hours	Days
1 second	1	0.0167	0.000278	0.0000116
1 minute	60	1	0.0167	0.000694
1 hour	3,600	60	1	0.0417
1 day	86,400	1,440	24	1
1 week	604,800	10,080	168	7
1 month (avg.)	2,629,800	43,830	730.5	30.44
1 year (365.25 d)	31,557,600	525,960	8,766	365.25

All calculations run locally in your browser, no data is stored or transmitted.

---

How many seconds in a year?

The exact answer depends on how you define a year:

• 365-day year (common): 365 x 24 x 60 x 60 = 31,536,000 seconds
• 365.25-day year (Julian average, accounts for leap years): 31,557,600 seconds
• 365.2422-day year (Gregorian/tropical year, true solar year): 31,556,926 seconds

Which should you use?

• For general calculations and project planning: 365 days (31,536,000 seconds)
• For scientific and astronomical calculations: 365.25 days (31,557,600 seconds)
• For high-precision solar calculations: 365.2422 days

Why 365.25? The Earth takes approximately 365.25 days to orbit the sun. The Gregorian calendar adds a leap day every 4 years to compensate, averaging 365.25 days per year. This is why the Julian year used in many scientific contexts is exactly 365.25 days.

---

The month problem

"Month" is the most ambiguous time unit in common use. Calendar months range from 28 to 31 days:

Month	Days
January, March, May, July, August, October, December	31 days
April, June, September, November	30 days
February (non-leap year)	28 days
February (leap year)	29 days

Standard averages used in time calculations:

• 30 days per month (simple round number, commonly used)
• 30.44 days per month (365.25 / 12 = 30.4375, the Julian average)
• 30.437 days per month (365.2422 / 12, the Gregorian average)

In practice: For contract terms, billing cycles, and project planning, months usually mean calendar months, check the specific number of days in the relevant months. For timespan calculations (how many months in X days), use 30.44 as the average.

For calculations involving specific dates (how many days between two dates, what day is 90 days from today), ToolHQ's date calculator handles calendar-aware date arithmetic.

Mini-story 1: Diego was setting up uptime monitoring for his company's web service. The SLA promised "99.9% uptime per year." He needed to know how many seconds of downtime that allowed. He entered 1 year into ToolHQ's time converter and got 31,536,000 seconds (using the 365-day year). 0.1% of that is 31,536 seconds; about 8.76 hours of allowed downtime per year. The operations team set the alert threshold at 8 hours and scheduled maintenance windows to stay within this budget.

Convert time units free at ToolHQ

---

How to use the ToolHQ time converter

1. Go to the tool. Navigate to ToolHQ's time converter. No account or sign-up required.
2. Enter your value. Type any number in the input field.
3. Select your source unit. Choose from seconds, minutes, hours, days, weeks, months, or years.
4. Read all results. The converter returns the equivalent in all supported units simultaneously.

---

Common time conversions for reference

Scenario	Value	Converted
Standard work week	40 hours	2,400 minutes / 144,000 seconds
10,000 hours (mastery rule of thumb)	10,000 hours	416.7 days / 1.14 years
1 million seconds	1,000,000 seconds	11.57 days / 277.8 hours
1 billion seconds (approx. age 31.7 years)	1,000,000,000 seconds	31.7 years
90-day contract term	90 days	2,160 hours / 7,776,000 seconds
6-month project	6 months (avg.)	182.6 days / 4,382 hours
Server uptime (99.9% in a year)	99.9% x 365 days	8.76 hours downtime allowed
Project sprint (2 weeks)	2 weeks	14 days / 336 hours

Mini-story 2: Priya was a project manager calculating whether her team had enough time to complete a development sprint before a major release. The release was in 6 weeks. The project required approximately 480 hours of development work across 4 developers. She entered 6 weeks into ToolHQ's time converter and got 1,008 hours (6 x 7 x 24). With 4 developers at 40 hours per week: 4 x 6 weeks x 40 hours = 960 available development hours. The 480-hour estimate fit within 960 available hours, giving a 50% buffer for testing, reviews, and unexpected issues.

---

Frequently asked questions

How many hours are in a year?

Using the 365-day year: 365 x 24 = 8,760 hours. Using the 365.25-day Julian average: 8,766 hours. For most planning purposes, 8,760 hours is the standard figure.

How many seconds are in a day?

Exactly 86,400 seconds (24 x 60 x 60). This is a fixed number because the day is defined as exactly 24 hours in civil timekeeping (leap seconds aside).

How many weeks in a year?

52.18 weeks (365.25 / 7). Equivalently, a year has 52 complete weeks plus 1 day (or 2 days in a leap year). For payroll and scheduling, most years have 52 pay weeks.

What is the average number of days in a month?

30.44 days, calculated as 365.25 days per year divided by 12 months. Individual calendar months range from 28 to 31 days. For time calculations, use 30.44 as the average unless you need to work with a specific month.

How do I convert hours to days?

Divide hours by 24. Example: 72 hours / 24 = 3 days. For partial days: 100 hours / 24 = 4.17 days (4 days and about 4 hours).

How do I convert days to seconds?

Multiply by 86,400. Example: 7 days x 86,400 = 604,800 seconds. This is useful for software systems that work with Unix timestamps or timer durations in seconds.

Is the time converter free?

Yes. ToolHQ's time converter is completely free, with no account, no sign-up, and no usage limits.

---

The short version

Time conversions are exact for units up through weeks (1 week = 7 days = 168 hours = 10,080 minutes = 604,800 seconds). Month and year conversions require a choice of definition: use 365 days for planning, 365.25 for scientific work. The most commonly needed reference is that 1 year = 31,536,000 seconds (365 days) or 31,557,600 seconds (365.25 days). ToolHQ's time converter handles seconds through years and returns all equivalents simultaneously.

For date-specific calculations, ToolHQ's date calculator handles calendar date arithmetic, the countdown timer tracks time remaining to a target date, and the days until calculator shows days until any future event. Explore more converter tools at ToolHQ.

Convert time units free at ToolHQ

---