You can provide the default value 0 on the actual property bound to v-model from data object itself. <v-text-field> is just a wrapper around an html <input>. Hence, it will bind the data in same way how we are binding for input.

Demo :

new Vue({
  el: '#app',
  vuetify: new Vuetify(),
  data: () => ({
    textFieldValue: 0,
  })
})

<link href="https://cdn.jsdelivr.net/npm/vuetify@2.x/dist/vuetify.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/vue@2.x/dist/vue.js"></script>
<script src="https://cdn.jsdelivr.net/npm/vuetify@2.x/dist/vuetify.js"></script>

<div id="app">
    <v-text-field v-model="textFieldValue"/>
  </div>
</div>

You can use the v-model directive and just set the default value to 0 in your data property. Example: <v-text-field v-model="textField" label="My Text Field/> and in your data: data: () => ({ textField: 0, })

Hope it's the right answer, cheers