Math & study

7 tools: GPA calculator, Scientific calculator, Fraction calculator, Standard deviation calculator, Roman numeral converter, Number to words converter, Number base converter. All tools are free of cost and do not require registration.

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GPA calculator

GPA = total of (credits × grade points) ÷ total credits. For example, an A and a B of 3 credits each give (3 × 4 + 3 × 3) ÷ 6 = 3.5 on the 4.0 scale.

  • Calculates a credit-weighted GPA and, if required, a cumulative GPA.
  • Converts letter grades on the 4.0 and 4.3 scales, and marks out of 100.
  • For other scales, the grade points can be entered directly.
Calculate GPA

Worked examples

Five classes: A, A, A, B and C (equal credits)
GPA 3.40
Weighted by credits: A (3), B (4), C (2), A (1)
GPA 3.20
4.3 scale: A+ (3 credits), A- (2), B (3)
GPA 3.66
Marks out of 100: 90 (3 credits) and 75 (2 credits)
GPA 3.42 · Weighted average marks 84

Scientific calculator

A full expression is calculated in the standard order of operations: 2 + 3 × 4 = 14, sin 30° = 0.5 and log 1000 = 3. Use the keyboard or the on-screen keys, in degrees or radians.

  • Calculates trigonometric and inverse functions, ln, log, powers, roots and factorials.
  • Works in degrees or radians, with results to 12 significant digits.
  • Accepts keyboard input and lists the calculations made on this page.
Open the calculator

Worked examples

2 + 3 × 4
14
(2 + 3) × 4
20
-2^2
-4
2^10
1024

Fraction calculator

To add fractions, first write them over a common denominator: 1/2 + 1/3 = 3/6 + 2/6 = 5/6 ≈ 0.833. This calculator works with fractions and mixed numbers, simplifies the answer and shows each step.

  • Adds, subtracts, multiplies and divides fractions and mixed numbers.
  • Simplifies the answer and shows each step.
  • Converts fractions to decimals, with repeating digits marked, and decimals to fractions.
Calculate fractions

Related pages

Worked examples

1/2 + 1/3
5/6 = 0.8(3)
3/4 − 5/6
−1/12 = −0.08(3)
Mixed numbers: 2 1/3 × 3/4
7/4 = 1 3/4 = 1.75
5/6 ÷ 2/3
5/4 = 1 1/4 = 1.25

Standard deviation calculator

Standard deviation measures how far a set of numbers is spread from the mean. For 2, 4, 4, 4, 5, 5, 7 and 9 the mean is 5, the population standard deviation is 2 and the sample standard deviation is about 2.138.

  • Gives the sample and population standard deviation and variance.
  • Also gives the mean, median, mode and range.
  • Shows the deviation of each number and every step.
Calculate standard deviation

Related pages

Worked examples

Eight values: 2, 4, 4, 4, 5, 5, 7, 9
Mean x̄ 5, Median 4.5, Sample standard deviation s 2.138089935, Population standard deviation σ 2
1 to 10
Mean x̄ 5.5, Median 5.5, Sample standard deviation s 3.027650354, Population standard deviation σ 2.872281323
Three marks: 85, 90, 78
Mean x̄ 84.33333333, Median 85, Sample standard deviation s 6.027713773, Population standard deviation σ 4.921607687
Two modes: 1, 2, 2, 3, 3, 4
Mean x̄ 2.5, Median 2.5, Sample standard deviation s 1.048808848, Population standard deviation σ 0.9574271078

Roman numeral converter

Roman numerals combine I (1), V (5), X (10), L (50), C (100), D (500) and M (1000). A smaller numeral written before a larger one is subtracted: 4 = IV, 9 = IX and 2026 = MMXXVI.

  • Converts numbers from 1 to 3999 to Roman numerals and back.
  • Writes dates in Roman numerals, in the order you choose.
  • Includes a chart from 1 to 100 and the Unicode characters.
Convert Roman numerals

Worked examples

2026 in Roman numerals
MMXXVI
1994 in Roman numerals
MCMXCIV
The largest standard numeral, 3999
MMMCMXCIX
XLIX as a number
49

Number to words converter

1,234,567 in words is one million two hundred thirty-four thousand five hundred sixty-seven. In the Indian system, 12,34,567 is twelve lakh thirty-four thousand five hundred sixty-seven.

  • Writes numbers and decimals in English words.
  • Writes amounts in words for cheques, in 6 currencies.
  • Supports the international and Indian (lakh, crore) systems.
Convert number to words

Worked examples

1,234,567 (international system)
one million two hundred thirty-four thousand five hundred sixty-seven
12,34,567 (Indian system)
twelve lakh thirty-four thousand five hundred sixty-seven
25,00,00,000 (Indian system)
twenty-five crore
1,00,000 crore (Indian system)
one lakh crore

Number base converter

Decimal 255 is 11111111 in binary, 377 in octal and FF in hexadecimal. Enter a number and its base to see it in the other bases, with the place values and repeated division shown.

  • Converts between binary, octal, decimal and hexadecimal.
  • Supports any base from 2 to 36 and very large numbers.
  • Shows the place values and the repeated division.
Convert number bases

Worked examples

Decimal 255 to binary
Binary 1111 1111
Decimal 255 to hexadecimal
Hexadecimal FF
Binary 1011 to decimal
Decimal 11
Hexadecimal 7E9 to decimal
Decimal 2 025