Calculator
- How I add or subtract dates without counting calendar squares
Date math is easy to get wrong because months have different lengths and weekends may or may not count. The Date Calculator tool handles the repetitive part so I can focus on checking whether the result makes sense.
- How I calculate age accurately for forms and records
Age sounds simple, but exact age depends on the date you measure against. The Age Calculator tool handles the repetitive part so I can focus on checking whether the result makes sense.
- How I calculate interest without hiding the assumptions
Interest calculations depend heavily on method: flat, effective, annuity, compound, tiered, or after-tax. I use Interest Calculator for the quick version of this task, then I review the output before relying on it.
- How I calculate loan payments before borrowing
A loan calculator helps me see the monthly payment, total interest, and how extra payments change the schedule. I use Loan Calculator for the quick version of this task, then I review the output before relying on it.
- How I calculate percentages without doing mental math
Percentages are simple until the question changes: percentage of, percentage increase, percentage decrease, and reverse percentage are different tasks. The Percentage Calculator tool handles the repetitive part so I can …
- How I convert fuel economy units without comparing the wrong direction
Fuel economy units can be confusing because km/L and MPG get better when the number is higher, while L/100 km gets better when the number is lower. I use Fuel Economy Converter for the quick version of this task, then I …
- How I convert temperatures without mixing Celsius and Fahrenheit
Temperature conversion is simple, but mistakes happen when the scale is not written clearly. I use Temperature Converter for the quick version of this task, then I review the output before relying on it.
- How I evaluate math expressions with variables without opening a spreadsheet
A math evaluator is useful when the calculation is more than a simple calculator entry but not big enough for a spreadsheet. I use Math Evaluator for the quick version of this task, then I review the output before …