Welcome folks today in this blog post we will be building a bmi calculator in python using pyqt5 library. All the full source code of the application is shown below.

Get Started

In order to get started you need to install the following libraries using the pip command as shown below

pip install pyqt5

After installing the library you need to make an app.py file and copy paste the following code

app.py

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'ayush.ui'
#
# Created by: PyQt5 UI code generator 5.11.2
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import (QWidget, QSlider,
    QLabel, QApplication)
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPixmap
import sys

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(927, 506)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
        MainWindow.setSizePolicy(sizePolicy)
        MainWindow.setMinimumSize(QtCore.QSize(927, 506))
        MainWindow.setMaximumSize(QtCore.QSize(927, 506))
        icon = QtGui.QIcon()
        icon.addPixmap(QtGui.QPixmap("../Downloads/fb-icon-9.png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        MainWindow.setWindowIcon(icon)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.plainTextEdit = QtWidgets.QPlainTextEdit(self.centralwidget)
        self.plainTextEdit.setGeometry(QtCore.QRect(210, 330, 511, 111))
        self.plainTextEdit.setObjectName("plainTextEdit")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(420, 250, 93, 28))
        self.pushButton.clicked.connect(self.button_click)
        self.pushButton.setObjectName("pushButton")
        self.horizontalSlider_2 = QtWidgets.QSlider(self.centralwidget)
        self.horizontalSlider_2.setGeometry(QtCore.QRect(198, 140, 541, 31))
        self.horizontalSlider_2.setOrientation(QtCore.Qt.Horizontal)
        self.horizontalSlider_2.setFocusPolicy(Qt.NoFocus)
        self.horizontalSlider_2.setRange(1, 150)

        self.horizontalSlider_2.valueChanged.connect(self.valu2)


        self.horizontalSlider_2.setObjectName("horizontalSlider_2")
        self.lineEdit_2 = QtWidgets.QLineEdit(self.centralwidget)
        self.lineEdit_2.setGeometry(QtCore.QRect(760, 130, 101, 51))
        self.lineEdit_2.setObjectName("lineEdit_2")
        self.lineEdit_2.textChanged.connect(self.value4)
        self.label_2 = QtWidgets.QLabel(self.centralwidget)
        self.label_2.setGeometry(QtCore.QRect(70, 130, 111, 51))
        font = QtGui.QFont()
        font.setPointSize(12)
        self.label_2.setFont(font)
        self.label_2.setObjectName("label_2")
        self.lineEdit = QtWidgets.QLineEdit(self.centralwidget)
        self.lineEdit.setGeometry(QtCore.QRect(760, 50, 101, 51))
        self.lineEdit.setObjectName("lineEdit")
        self.lineEdit.textChanged.connect(self.value3)



        self.horizontalSlider = QtWidgets.QSlider(self.centralwidget)
        self.horizontalSlider.setGeometry(QtCore.QRect(200, 50, 541, 31))
        self.horizontalSlider.setOrientation(QtCore.Qt.Horizontal)
        self.horizontalSlider.setFocusPolicy(Qt.NoFocus)
        self.horizontalSlider.setRange(1, 200)

        self.horizontalSlider.valueChanged.connect(self.valu)
        self.horizontalSlider.setObjectName("horizontalSlider")


        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setGeometry(QtCore.QRect(70, 50, 91, 31))
        font = QtGui.QFont()
        font.setPointSize(12)
        self.label.setFont(font)
        self.label.setObjectName("label")
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def valu2(self):
        self.k = str(self.horizontalSlider_2.value())
        self.lineEdit_2.setText(self.k)


    def valu(self):
        self.a = str(self.horizontalSlider.value())
        self.lineEdit.setText(self.a)

    def value3(self):
        self.j=str(self.lineEdit.text())
        self.horizontalSlider.setSliderPosition(int(self.j))
        if int(self.j)==0:
            self.horizontalSlider.setSliderPosition(int(1))

    def value4(self):
        self.j=str(self.lineEdit_2.text())
        self.horizontalSlider_2.setSliderPosition(int(self.j))
        if int(self.j)==0:
            self.horizontalSlider.setSliderPosition(int(1))


    def button_click(self):
        self.j = int(self.lineEdit_2.text())
        self.k = int(self.lineEdit.text())
        self.bmi =self.j/((self.k/100)**2)
        self.string="your body mass index is "+str(self.bmi)
        print (self.string)
        self.plainTextEdit.setPlainText(self.string)


    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "BMI"))
        self.pushButton.setText(_translate("MainWindow", "calculate"))
        self.label_2.setText(_translate("MainWindow", "weight"))
        self.label.setText(_translate("MainWindow", "height"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

Now if you run the python script by typing the below command as shown below

python app.py