Reliable Online
Calculators
& Everyday Tools

Use our age calculator with today's date. It calculates total days automatically by counting every day from your birth date to now, accounting for leap years. You can also see the breakdown in years, months, and days simultaneously.

If today's date is before your birthday this year, we subtract one year. For example, if you were born in July and today is March, you haven't turned that year's age yet. The tool handles this automatically.

Yes. Our calculator handles leap year birthdays correctly. On non-leap years, the birthday is treated as March 1 for counting purposes, which is the most widely accepted standard.

Yes — the tool lets you change the reference date. Want to know how old someone was on a specific day in history, or how old they'll be in 10 years? Just change the "As of date" field.

Multiply the number by the percentage, then divide by 100. Example: 20% of 150 = (150 × 20) ÷ 100 = 30. Or just use the "% of Number" mode in our calculator — enter 20 and 150 and hit Calculate.

Formula: ((New Value − Old Value) ÷ Old Value) × 100. A positive result is an increase; negative is a decrease. Example: from 80 to 100 = ((100−80)÷80)×100 = 25% increase. Use "% Change" mode in the calculator.

The basic formula is Percentage = (Part ÷ Whole) × 100. Rearranged: Part = (Percentage ÷ 100) × Whole, and Whole = Part ÷ (Percentage ÷ 100). All three versions are covered by our four calculator modes.

Use "% of Number" mode. Enter the tip percentage (e.g. 15) and the bill total (e.g. 85). Result: $12.75. For a 20% tip on $85, the answer is $17. You can split the total among people manually after.

Convert each letter grade to its point value (A=4.0, B=3.0, C=2.0, D=1.0, F=0), multiply by credit hours to get quality points, add all quality points, then divide by total credit hours. Our calculator does all of this automatically — just select your grades from the dropdown.

3.5 and above is generally considered excellent (dean's list territory at most schools). 3.0 is good and competitive for most graduate programs. A 2.0 is typically the minimum to stay in good academic standing. For highly competitive grad schools or medical school, 3.7+ is usually needed.

It depends on how many credits you've completed. Early in college, one bad semester has a large impact. Later, your GPA becomes harder to move because it's the weighted average of many more credits. Use our Cumulative GPA mode to model the exact impact before it happens.

Most universities require a 3.5 semester GPA for the dean's list, though some set it at 3.7 or 3.8. Use our Semester GPA calculator to test different grade combinations and see which ones get you there before grades are finalised.

Open the Random Number Generator, select "Single Number" mode, enter 1 as the minimum and 100 as the maximum, then click Generate. You'll get a random integer in that range instantly. Click again for a new number.

It uses the Web Crypto API (crypto.getRandomValues), which is cryptographically strong — far more unpredictable than basic Math.random(). Each number is statistically independent from all previous results. It's suitable for giveaways, games, and sampling.

Yes. Assign a number to each participant starting at 1, set your range from 1 to the total number of entries, and generate. The result is statistically fair and unbiased. Use Single Number mode for a single winner, or Multiple mode for multiple prizes.

Use Lottery Picker mode. Set the minimum to 1, maximum to 49 (or your lottery's max), and "Pick" to 6 (or however many numbers your lottery draws). The tool picks unique random numbers with no repeats — just like real lottery balls.

The dice roller supports D4, D6, D8, D10, D12, D20, and D100 — all standard RPG dice. You can roll multiple dice at once and see the total plus a breakdown of individual rolls. Perfect for Dungeons & Dragons, Pathfinder, and other tabletop games.