How to make calculator using kivy | Python (original) (raw)

Last Updated : 12 Jul, 2025

Kivy is a platform-independent GUI tool in Python. As it can be run on Android, IOS, linux and Windows etc. It is basically used to develop the Android application, but it does not mean that it can not be used on Desktops applications.

???????? Kivy Tutorial - Learn Kivy with Examples.

In this article, we will learn how to make a simple calculator using Kivy.

Prerequisites:

Basic knowledge of Mathematics

Python

Kivy

Widgets and code understanding of kivy

Basic approach to make A calculator:

import kivy
import kivyApp
import Gridlayout
import config(to configure/adjust the window size)
Set minimum version(optional)
Create Layout class : define Calculator function in it : In this i am using try-catch because if any arithmetic exception occur it will through the error
create App class
create .kv file (name same as the app class): 1) create buttons 2) Add the style to the buttons 3) Add functionalities of the button
return Layout/widget/Class(according to requirement)
Run an instance of the class

Implementation of the Approach:
main.py

Python3 `

Program to create a calculator

Program to Show how to create a switch

import kivy module

import kivy

base Class of your App inherits from the App class.

app:always refers to the instance of your application

from kivy.app import App

this restrict the kivy version i.e

below this kivy version you cannot

use the app or software

kivy.require('1.9.0')

for making multiple buttons to arranging

them we are using this

from kivy.uix.gridlayout import GridLayout

for the size of window

from kivy.config import Config

Setting size to resizable

Config.set('graphics', 'resizable', 1)

Config.set('graphics', 'width', '400')

Config.set('graphics', 'height', '400')

Creating Layout class

class CalcGridLayout(GridLayout):

# Function called when equals is pressed
def calculate(self, calculation):
    if calculation:
        try:
            # Solve formula and display it in entry
            # which is pointed at by display
            self.display.text = str(eval(calculation))
        except Exception:
            self.display.text = "Error"

Creating App class

class CalculatorApp(App):

def build(self):
    return CalcGridLayout()

creating object and running it

calcApp = CalculatorApp() calcApp.run()

calculator.kv