JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgit.com/yyx990803/vue/master/dist/vue.js"></script>
<input type="number" v-model="celsius" value="0" />°C
<span> ⇄ </span>
<input type="number" v-model="fahrenheit" />°F

JavaScript

new Vue({
    el: 'body',
    computed: {
        fahrenheit: {
            $get: function() {
                return 9/5 * this.celsius + 32
            },
            $set: function(f) {
                this.celsius = 5/9 * (f - 32)
            }
        }
    }
})