Date & time calculators.

Save your exam goal, plan your study days, and turn focused sessions into progress.

Work out an exact age from any date of birth. Enter the birth date below to see the age in years, months and days, the total days and weeks lived, and the number of days until the next birthday.

Count the working days between two dates. Pick a country and the calculator removes weekends and that country's public holidays, so you see the real number of working days in the range.

Convert a dog's age into human years. This calculator uses the modern size-aware method rather than multiplying by seven, because a dog's first two years age much faster than the years after them.

Convert a cat's age into human years. Like dogs, cats age quickly in their first two years and then more steadily, so this calculator uses a stepped method rather than a single multiplier.

Estimate a due date and see how far along a pregnancy is. Choose the method that fits the information you have: last menstrual period, conception date, IVF transfer date, or a dating ultrasound.

Build a live countdown to any date. Enter a date, an optional time and an event name, then share the link so anyone can watch the same countdown tick down.

Estimate ovulation timing and a six-day fertile window from the first day of your last period and your usual cycle length. This calendar method assumes regular cycles; it cannot confirm ovulation.

Estimate when conception is likely to have happened. Work it back from a known due date, or forward from the first day of your last period and your cycle length.

Estimate a due date using the embryo age and transfer date supplied by your fertility clinic. Supports day-3 and day-5 embryos.

Find out which trimester you are in now, and see the dates each trimester begins and ends. Enter your information using whichever method you have: last period, conception date, IVF transfer or a dating ultrasound.

Estimate your current pregnancy weeks and days from a last-period date and cycle length, or use the estimated due date assigned by your healthcare provider.

Enter your exam date and target study hours to get a quick hours-per-day estimate across the calendar days remaining. For a plan that follows your chosen study days and tracks completed sessions, use the free study planner below. CPA, bar exam and USMLE calculators also show exam-specific results estimates.

Plan a CPA exam section and see when your score is likely to be released. Choose your section, enter your test date and a study hours target, and the calculator shows the days left, the hours per day to reach your target, and the AICPA target score-release date for that testing window.

Plan your bar exam preparation and see when results are usually released. Choose your state, enter your exam date and a study hours target, and the calculator shows the days left, the hours per day to reach your target, and the typical results-release date for your jurisdiction and sitting.

Plan a dedicated USMLE study block and see when results are usually reported. Choose your Step, enter your test date and a study hours target, and the calculator shows the days left, the hours per day to reach your target, and a typical results date.