Every page below answers one question in a sentence or two, then shows the working and ends with the live calculator, so you can check the answer against your own numbers. 30 explainers in total.
Learn
Short, plain-English answers to the questions behind the calculators, grouped by the calculator they belong to.
- 30 explainers
- Plain English
- Each with a live calculator
Average Calculator
1 explainer · Open the Average Calculator
- How to Find the AverageTo find the average, add up all the numbers and divide by how many there are.
Mode Calculator
1 explainer · Open the Mode Calculator
- What Is the Mode in Math?The mode is the value that appears most often in a set of numbers.
Grade Calculator
1 explainer · Open the Grade Calculator
- Is a D a Passing Grade?Usually yes: a D (60–69%) is the lowest passing grade in most US high schools and colleges.
GPA Calculator
15 explainers · Open the GPA Calculator
- What Is a Good GPA?A 3.0 is the common minimum, 3.5 is the honors line, 3.7+ is competitive for selective schools.
- Is a 4.0 GPA Good?Perfect: a 4.0 GPA is about a A.
- Is a 3.9 GPA Good?Excellent: a 3.9 GPA is about a A.
- Is a 3.8 GPA Good?Excellent: a 3.8 GPA is about a A-.
- Is a 3.7 GPA Good?Very good: a 3.7 GPA is about a A-.
- Is a 3.6 GPA Good?Very good: a 3.6 GPA is about a A-/B+.
- Is a 3.5 GPA Good?Good: a 3.5 GPA is about a B+.
- Is a 3.4 GPA Good?Good: a 3.4 GPA is about a B+.
- Is a 3.3 GPA Good?Good: a 3.3 GPA is about a B+.
- Is a 3.2 GPA Good?Above average: a 3.2 GPA is about a B.
- Is a 3.0 GPA Good?Average to good: a 3.0 GPA is about a B.
- Is a 2.7 GPA Good?Below average: a 2.7 GPA is about a B-.
- Is a 2.5 GPA Good?Below average: a 2.5 GPA is about a B-/C+.
- Is a 2.0 GPA Good?Minimum: a 2.0 GPA is about a C.
- What Is Cumulative GPA?Cumulative GPA is your grade point average across every term so far, weighted by credits.
Percentage Calculator
3 explainers · Open the Percentage Calculator
- How to Calculate the Percentage of a NumberTo find a percentage of a number, multiply the number by the percent and divide by 100.
- How to Calculate Percent ErrorPercent error = |measured − accepted| ÷ accepted × 100.
- How to Calculate Percentage DifferencePercentage difference = |a − b| ÷ ((a + b) ÷ 2) × 100.
Time Unit Converter
8 explainers · Open the Time Unit Converter
- How Many Seconds in a Day?There are 86,400 seconds in a day: 24 hours × 60 minutes × 60 seconds.
- How Many Minutes in a Day?There are 1,440 minutes in a day: 24 hours × 60 minutes.
- How Many Hours in a Week?There are 168 hours in a week: 7 days × 24 hours.
- How Many Seconds in an Hour?There are 3,600 seconds in an hour: 60 minutes × 60 seconds.
- How Many Hours in a Month?A month has 672 to 744 hours depending on its length; the average month is 730.5 hours.
- How Many Minutes in a Year?There are 525,600 minutes in a normal year and 527,040 in a leap year.
- How Long Is 72 Hours?72 hours is exactly 3 days (72 ÷ 24 = 3).
- How Long Is 90 Minutes?90 minutes is 1.5 hours, or 1 hour and 30 minutes.
Molecular Weight Calculator
1 explainer · Open the Molecular Weight Calculator
- How to find molar massMolar mass explained in plain English: what it is, how to work it out from a chemical formula step by step, worked examples for water, glucose and calcium hydroxide, and a calculator to check your answer.
Questions people ask
What is on the avgcalc learn pages?
Each learn page answers one question in plain English: how to find an average, what a good GPA is, how to calculate percent error, how long 72 hours is, and so on. Each one shows the working and ends with the calculator that does it for you.
Are the explainers free?
Yes. Every page and every calculator on avgcalc is free, with no account and no usage limit, and nothing you type into a calculator leaves your browser.
How do I find the right explainer?
They are grouped above by the calculator they belong to, so start from the calculator you want (average, GPA, percentage, time) and the questions under it are the ones people ask about that calculator.