Scientific Calculator and Exact Age Calculator Online

How to use the scientific and age calculator

Scientific calculator

1. Tap the keys or type on your keyboard to build an expression, for example 2 × sin(30) + √(16).
2. Check the DEG/RAD key. DEG treats angles as degrees; RAD treats them as radians.
3. Press = or Enter. The expression appears above the answer so you can check it.
4. Keep calculating from the answer with an operator, or type a number to start fresh.

Age calculator

1. Open the Age Calculator tab and pick your date of birth.
2. Leave the second date as today, choose any other date, or press 1 August this year to check UPSC age eligibility.
3. Read your age in years, months and days, plus total weeks, total days and the days left to your next birthday.

How the calculations work

Order of operations

Powers are right-associative, so 2^3^2 = 2^9 = 512. A number next to a bracket or constant is multiplied, so 2π = 6.2832 and 3(4 + 1) = 15. The calculator reads your expression with its own parser instead of running it as code, so nothing typed can execute as a script.

Exact age method

Age is counted in calendar months, not as a number of days divided by 365. The tool finds the last monthly anniversary of your birth date on or before the chosen date, then counts the days after it. When a month is too short (31 January plus one month), the anniversary moves to the last day of that month.

Tips for exam forms and CSAT practice

• UPSC age limit: for CSE 2026 the official notification requires a candidate to have attained 21 years and not attained 32 years on 1 August 2026 (General category), with relaxations for other categories.
• Other exams use other cut-off dates. Always read the age-reckoning date in your own notification and enter that date here.
• Trigonometry check: sin 30° = 0.5, cos 60° = 0.5 and tan 45° = 1. If you get −0.988 for sin(30), you are in radian mode.
• Logs: log is base 10 and ln is base e. log(1000) = 3 and ln(e) = 1.

Frequently asked questions

How is exact age calculated in years, months and days?

The calculator counts the whole years and months from your date of birth to the chosen date, then counts the remaining days. For example, from 2 August 2001 to 1 August 2026 is 24 years, 11 months and 30 days.

How is age calculated for someone born on 29 February?

In a non-leap year, this calculator treats 28 February as the completed birthday, because the month has no 29th. So a person born on 29 February 2000 is exactly 1 year old on 28 February 2001, and 1 year and 1 day old on 1 March 2001.

How do I check my age for the UPSC Civil Services Examination?

UPSC reckons age on 1 August of the examination year. Press the 1 August button, enter your date of birth and read your age; for CSE 2026, a General category candidate must have been born between 2 August 1994 and 1 August 2005.

Should I use degree or radian mode for trigonometry?

Use degree mode (DEG) for angles written in degrees, such as sin 30° = 0.5, which is what most school and competitive exam questions use. Switch to RAD when the angle is in radians, for example sin(π/6) = 0.5.

In what order does the scientific calculator work out an expression?

It follows standard operator precedence: brackets first, then powers, then multiplication and division, then addition and subtraction. So 2 + 3 × 4 = 14, and −2^2 = −4 because the power is applied before the minus sign.

What do the % and n! buttons do?

The % button divides the number before it by 100, so 200 × 10% = 20. The n! button gives the factorial of a whole number, so 5! = 120; factorials of negative or decimal numbers are not supported.