calculator
General
| Common Equivalent Weigths and Measures | Univeristy of California Berkeley |
| Great Circle Calculator | Calculate the distance in a straight line between any two points on the globe. |
| Measure4Measure | Annotated lists of links to sites relating to measuring, converting measurements, etc. Arranged under four subjects: Science/Math, Health, Finance, Everything Else. |
| Online Conversions | Robert Fogt. Convert distance, speed, temperature, volume, weight, etc - 5,000 units, 50,000 conversions. |
Money
| Foreign Exchange Rates | Federal Reserve Bank of New York. |
| How Much is it Worth Today? | Compare the value of an amount of money in the past with the present, or with another time in the past, 1665-present. |
| Universal Currency Converter | XE.com. Convert world currencies and metals at live currency rates. |
| What is a Dollar Worth | Federal Reserve Bank of Minneapolis. Enter any amount of money to find out how much it is worth at another time, from 1913 to the present. Estimates are available for 1800 to the present. |
Time
| Calendars Through the Ages | Institute for Dynamic Educational Advancement. Chinese, Christian, Julian, Indian, Islamic, Jewish, Gregorian, French, Future, Mayan, and Roman calendars. Information on the year and the seven-day week. |
| Perpetual Calendar | Michael Bertrand. View the calendar for any year, 1582 - present. |
| Time Zone Converter | Choose countries or regions and find simultaneous times in both areas. |
| World Time Server | iSBiSTER International. Find out what time it is anywhere in the world. |
| World Time Zone Map | U.S. Naval Observatory. |