JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.css">
<script src="https://code.jquery.com/jquery-3.4.1.slim.js"></script>
<form name="formular1">
<div class="input-group">
<div class="titel">Zeile1</div>
<div class="wert"><input id="Wert11" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert12" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert13" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert14" value="" onkeyup="j_calculate()"/></div>
<div class="summe"><input id="Wert1"></div>
</div>
<div class="input-group">
<div class="titel">Zeile2</div>
<div class="wert"><input id="Wert21" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert22" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert23" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert24" value="" onkeyup="j_calculate()"/></div>
<div class="summe"><input id="Wert2"></div>
</div>
<div class="input-group">
<div class="titel">Zeile3</div>
<div class="wert"><input id="Wert31" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert32" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert33" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert34" value="" onkeyup="j_calculate()"/></div>
<div class="summe"><input id="Wert3"></div>
</div>
<div class="input-group">
<div class="titel">Erg: 4</div>
<div class="wert"><input id="Wert41" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert42" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert43" value="" onkeyup="j_calculate()"/></div>
<div class="wert"><input id="Wert44" value="" onkeyup="j_calculate()"/></div>
<div class="summe"><input id="Wert4"></div>
</div>
</form>

JavaScript

function j_calculate() {

function rechnen(spalte) {
	let summe=0;
	for (let i=1; i<=4; i++) {
		summe += getInputAsFloat(document.formular1["Wert"+spalte+i]);
		}
document.getElementById("Wert"+spalte).value= summe;	
}	

function rechnen_s4() {
let summe=0;
for (let i=1; i<4; i++) {
	summe = getInputAsFloat(document.formular1["Wert1"+i] )+
	getInputAsFloat(document.formular1["Wert2"+i] )+
	getInputAsFloat(document.formular1["Wert3"+i] );
	document.getElementById("Wert4"+i).value= summe;	
	}
}	

function getInputAsFloat(element)
 { return (element
         ? parseFloat(element.value.replace(/[^0-9 ]/g, "")) || 0
         : 0);
 }
  
  rechnen(1);
  rechnen(2);
  rechnen(3);
    rechnen(4);
rechnen_s4();


}