Formula custom calculator

When using a calculator to calculate, there is a problem that wastes time: users will have to re-enter the same calculation formula many times.

The Formula custom calculator application solves that problem by helping users create their own formulas and save them for repeated use.

When using, the user only takes the saved formula and enters the variables, the expression value will be automatically calculated.
For example, users can enter a formula to convert length units
[Miles = 1.60934 * Km].
When calculating, users only need to enter the Km value,
the Miles value will be automatically calculated.

Similarly, users can enter unlimited of their own commonly used formulas such as percent increase calculator, cubic feet calculator, square footage calculator...

This will save time on repeating the same calculations.

In addition, the Formula custom calculator application also functions as a scientific calculator.
Users can calculate like a regular calculator or switch to calculation mode according to the created formula.