JSFiddle - React, Tailwind, and code Playground

HTML

<section>
   <!--- Celsius, Fahrenheit, Kelvin  -->
   <table>
     <tr>
       <td>&#176C</td>
       <td>&#176F</td>
       <td>&#176K</td>
     </tr>
     <tr>
       <td> <input type="number" id="celsius"/> </td>
       <td id="fahr1"></td>
       <td id="kelv1"></td>
     </tr>
     <tr>
       <td id="celc2">-</td>
       <td> <input type="number" id="fahrenheit" /> </td>
       <td id="kelv2">-</td>
     </tr>
   </table>
 </section>

JavaScript

$('input[type=number]').change(function() {
 if($(this).attr('id') == 'celsius'){
     $('#fahr1').text(celsiusToFahrenheit($(this).val()));
     $('#kelv1').text(celsiusToKelvin($(this).val()));
 }
 else if($(this).attr('id') == 'fahrenheit'){
    $('#celc2').text(fahrenheitToCelsius($(this).val()));
    $('#kelv2').text(fahrenheitToKelvin($(this).val()));
  }
});

function celsiusToFahrenheit(c) {
    var f = parseInt(c);
    f = f * (9/5) + 32;
    return f;
}

function celsiusToKelvin(c) {
    var k = parseInt(c);
    k = k + 273.15;
    return k;
 }

function fahrenheitToCelsius(f) {
     var c = parseInt(f);
     c = (c - 32) * (5/9);
    return c;
}

function fahrenheitToKelvin(f) {
    var k = parseInt(f);
    k = (k + 459.67) * (5/9);
   return k;
}