Running
Average Half Marathon Times by Age
A half marathon is 21.0975 km. Wide planning ranges by age, the pace at each end, and why a published average is a weak target.
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CalculateWise Blog
How the calculators work, with the formulas and the cases where a single number is the wrong target.
Running
Average Marathon Times by Age
Marathon planning ranges by age, with the pace at each end. These are coaching bands, not race medians. A 4:00 marathon is 5:41 per kilometer at every age.
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Running
Average Running Pace by Age and Distance
Age does not change the pace math. Wide recreational planning ranges for 5K, 10K, half marathon, and marathon, plus the pace each clock time requires.
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Running
Average Running Speed by Age
There is no single average running speed for an age. These are wide easy-run planning ranges, not survey results, plus how to judge your own pace.
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Running
How Much Faster to Cut 5 Minutes Off a 10K
Five minutes off a 10K is 30 seconds per kilometer, or about 48 seconds per mile. Worked examples from 60:00, 55:00, and 50:00.
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Health
Due Date From Ovulation or Conception Date
Add 266 days to an ovulation date or a conception date. A worked example, why both dates use the same rule, and when the period method is the better start.
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Health
How Accurate Are Pregnancy Due Dates?
A due date is the 40-week mark from a period, or 38 weeks from ovulation. Most births are not on that exact day. What moves the estimate, and what replaces it.
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Running
How Long Does a 10K Take?
10K pace chart from 40:00 to 1:10:00. A 10K is 10 kilometers, or 6.214 miles, with the halfway split at even pace.
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Running
How Long Does a 5K Take?
5K pace chart from 20:00 to 40:00. A 5K is 5 kilometers, or 3.107 miles. Each finish time with min/km, min/mile, and speed.
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Running
How Long Does a Half Marathon Take?
A half marathon is 21.0975 km (13.109 miles). Finish times from 1:30 to 2:30, the pace each requires, and why doubling it is not a marathon plan.
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Running
How Long Does a Marathon Take?
Marathon pace chart from 2:30 to 6:00. A marathon is 42.195 km (26.219 miles). Each finish time with min/km, min/mile, and the 5K split.
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Health
How Many Days Is a Pregnancy?
280 days (40 weeks) from the last menstrual period, or 266 days (38 weeks) from conception. Same model, different starting point, plus the term labels clinicians use.
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Health
How Many Weeks Pregnant Am I?
Divide days since the first day of the last period by 7. A worked example, why that count is about two weeks ahead of conception, and where months differ.
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Running
How to Calculate Running Pace
Divide time by distance to get running pace in min/km or min/mile, then turn that pace into speed. A 5 km example worked through both units.
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Running
How to Run a Sub-4 Hour Marathon
A 4:00 marathon is 5:41 per kilometer or 9:09 per mile. Checkpoints, the 5K split, and what a shorter race has to look like before that goal is realistic.
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Running
Minutes per Kilometer vs Minutes per Mile
Minutes per mile to minutes per kilometer chart. Min/km times 1.609344 equals min/mile. A 5:00 kilometer is 8:03 per mile.
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Health
Ovulation Date vs Conception Date
Ovulation is the egg release. Conception is fertilization, usually within about a day. Implantation is later and is not the start of the 266-day due-date count.
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Health
Pregnancy Trimester Dates Explained
First trimester through week 12, second from week 13, third from week 28. Calendar dates for a 1 January period, and how months overlap those boundaries.
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Health
Pregnancy Weeks to Months Chart
Pregnancy months are unequal groups of weeks, not weeks divided by four. The chart from month 1 through month 9, plus the calendar-month alternative.
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Running
Running Pace vs Speed
Pace is minutes per kilometer or mile. Speed is kilometers or miles per hour. Here is the conversion and when each number is the useful one.
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Running
What Is a Good Running Pace?
A good running pace depends on distance and effort. Easy-run ranges, what 5K and marathon times imply, and why a single average is the wrong target.
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Education
The Crisis of Higher Ed: Calculating the True Cost of College
College costs are outpacing inflation. We analyze the 'Total Cost of Attendance,' the impact of loan interest, and how to plan for 2030 and beyond.
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Business
The 2026 Startup Financial Roadmap: Survival Math
Most startups fail due to cash flow, not product fit. Learn to calculate Burn Rate, Break-Even, and Runway to survive the 'Valley of Death'.
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Construction
Concrete Pouring Mistakes: Cold Joints, Water, and Bag Mix
After the volume estimate: cold joints, extra water, temperature, and when a bag mix should be a ready-mix truck.
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Ecology
Real-World Sustainability: Measuring Your Carbon Footprint in 2026
Going green is often vague. We put numbers to the concept, explaining how Carbon Footprints are calculated and which lifestyle changes actually move the needle.
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Health
Beyond BMI: Body Fat Percentage and TDEE
After the BMI formula: body-fat percentage ranges, the Navy tape method, and how TDEE differs from the height-and-weight ratio.
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Health
How Is a Pregnancy Due Date Calculated?
280 days from the last menstrual period, or 266 days from ovulation. Naegele’s rule, a cycle-length adjustment, and three worked examples. The result is an estimate.
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Financial
Protecting Your Wealth: Inflation, Salary, and Purchasing Power
A deep dive into how inflation erodes salary gains. Learn how to calculate your 'Real Wage' and adjust your financial strategy.
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Construction
Home Renovation Estimating: Paint, Tile, and Wallpaper Math
Renovations always go over budget. Why? Poor estimating. Learn how to calculate material needs including waste factors and pattern repeats.
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Financial
The Mathematics of Debt Freedom: Strategies for 2026
Debt is a mathematical emergency. We compare the Snowball vs. Avalanche methods and analyze the true cost of carrying a balance in a high-interest environment.
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Health
The Science of Energy Balance: TDEE, BMR, and Metabolism
The four parts of TDEE: BMR, daily movement, digestion, and exercise. Includes the activity setting that throws the estimate off.
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Financial
Retirement Planning in 2026: The Ultimate Strategy Guide
The 4% rule is under attack. Inflation is sticky. Longevity is increasing. Here is how to build a robust retirement plan given the economic realities of 2026.
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Financial
The 2026 Homebuyer's Financial Guide: Mortgage, DTI, and Rent vs. Buy
Buying a home in 2026 requires more than just a down payment. We break down the math of DTI ratios, interest rate impacts, and the 'Rent vs. Buy' equation in today's market.
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Education
How to Calculate the Final Grade You Need (To Pass or Get an A)
Stressing about finals? Learn the formula to calculate exactly what score you need on your final exam to achieve your target grade in the class.
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Financial
Gross Pay vs Net Pay: Where Does Your Money Go?
Why is your paycheck smaller than your salary? Learn the difference between gross and net pay, and understand the taxes and deductions that reduce your take-home amount.
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Financial
How to Estimate Your 2025 Tax Refund: A Complete Guide
Learn how to estimate your 2025 tax refund (filed in 2026). Understand tax brackets, deductions, and how to use a tax calculator to plan ahead.
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Health
What is TDEE and Why It Matters for Weight Loss
Stop guessing your calories. Learn what TDEE (Total Daily Energy Expenditure) is, how to calculate it, and how to use it to lose weight sustainably.
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Health
Why Your BMI Number Isn't the Whole Story
Body Mass Index is a useful starting point, but it doesn't measure your health. Here's a balanced look at what BMI can (and can't) tell you.
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Construction
Stop Buying Too Much Concrete: A Guide to Estimating
Learn how to calculate exactly how much concrete you need for your patio or driveway without wasting money on leftovers or coming up short.
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Financial
The Magic of 'Doing Nothing': Compound Interest Explained
Why starting early matters more than being smart. A simple explanation of how your money makes its own money.
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