Get subtotal, shipping total and Grand total in checkout page using js Magento 2.

You can get total related information in the checkout page with a subtotal, shipping charge, grand total using Javascript.

For getting update grand total with the shipping charge and tax total and other info you need to call ‘Magento_Checkout/js/model/totals’ in the JS file.

You need to call totals Objects with a required field,

define([
    'uiComponent',
    'Magento_Checkout/js/model/totals'
], function (Component,totals) {
    'use strict';

    return Component.extend({
        getGrandTotal: function(){
            if (totals.totals()) {
                var grandTotal = parseFloat(totals.totals()['grand_total']);
                return grandTotal;
            }
        },
        getSubTotal: function(){
            if (totals.totals()) {
                var subtotal = parseFloat(totals.totals()['subtotal']);
                return subtotal;
            }
        },
        getShippingAmount: function(){
            if (totals.totals()) {
                var shippingAmount = parseFloat(totals.totals()['shipping_amount']);
                return shippingAmount;
            }
        }
    });
});

You can call above function in template with getGrandTotal(), getShippingAmount() and getSubTotal().