Get ISO week numbers for any date — plan sprints and fiscal weeks correctly. Know Week 32 means late July instantly — free, local, no signup.
Find the weekday for any Gregorian date — plan anniversaries, verify old records, settle bets. Check what day you were born in seconds — free, no signup, runs locally.
Measure the exact gap between two dates in days, weeks, and months — tenures, ages, project spans. A 3-year job stint reads 1,096 days instantly — free, no signup, runs locally.
Convert any date to its day-of-year number (1–365/366) with days remaining. Developers compute ordinal dates for logs and filenames — free, no signup, runs locally.
Convert numbers between binary, octal, decimal, and hex with bitwise views. Read 0xFF as 255 instantly — local math, free, no signup.
Estimate due date from last period with trimester milestones. Get the 40-week roadmap instantly — free, local, informational only.
Weeks start Monday; week 1 contains the first Thursday (Jan 4 always in week 1). US Sunday-start systems differ — confirm which standard applies.
Most years have 52 ISO weeks; years starting Thursday (or leap years starting Wednesday) get 53. The tool reports correctly either way.
Name sprints by ISO week (2026-W32) for unambiguous cross-timezone references. Backlogs sort chronologically for free.
No — math runs locally in your browser. Nothing leaves your device.
Jan 1 2026 (a Thursday) gives Week 1; Dec 31 2026 gives Week 53. The tool counts the Jan 1–3 partial week as week 1 (week = ceil((dayOfYear + Jan-1 weekday) / 7)), so year-end spills to 53 — this is not the ISO-8601 rule, so cross-check for compliance use.
Percentage Calculator
Computes X% of Y and what-percent-of-what (X is what % of Y) in two side-by-side panels with precise decimal arithmetic. Essential for everyday math — tips, discounts, tax rates, grade scores, and statistical comparisons where quick percentage answers are needed.
Age Calculator
Computes exact age in years, months, and days from a given birth date relative to any target date. Numbers never leave your device — every calculation runs locally in your browser.
ETA Calculator
Estimate travel time from distance and speed — with optional arrival time and traffic buffer. Add traffic buffers and arrival targets for realistic plans — free, local, no signup.
Study Time Calculator
Plan study hours from syllabus weight and days left — pass with scheduled effort. Turn 5 chapters in 10 days into daily targets — free, local, no signup.
Test Score Calculator
Compute test percentages and grades from correct/total with curve options. Turn 42/50 into 84% (B) instantly — free, local, no signup.
Words Per Page Calculator
Estimate pages from word count and font size — about 500 words/page at 12pt, 600 at 10pt and under. Font-size-only math, no spacing or margin inputs — free, local, no signup.
Last updated October 2026