My Own Packaging
Prepaid Satchel – Small (355 x 225mm)
Prepaid Satchel – Medium (390 x 270mm)
Prepaid Satchel – Large (415 x 315mm)
Prepaid Satchel – Extra Large (510 x 440mm)
Cubic Weight:0.00 kg
Chargeable Weight:0.00 kg
Base Postage:$0.00
Extra Cover (Insurance):$0.00
Total Estimated Cost:$0.00
* This calculator estimates costs based on typical domestic rates. Actual costs may vary based on specific zones (metro/regional) and current fuel surcharges.
function calculatePostage() {
// 1. Get Inputs
var weightInput = document.getElementById('weight').value;
var lengthInput = document.getElementById('length').value;
var widthInput = document.getElementById('width').value;
var heightInput = document.getElementById('height').value;
var serviceType = document.getElementById('serviceType').value;
var itemValueInput = document.getElementById('itemValue').value;
var packagingType = document.getElementById('packagingType').value;
// 2. Parse values and handle validation
var weight = parseFloat(weightInput);
var length = parseFloat(lengthInput);
var width = parseFloat(widthInput);
var height = parseFloat(heightInput);
var itemValue = parseFloat(itemValueInput);
if (isNaN(itemValue)) itemValue = 0;
// If using own packaging, dimensions and weight are mandatory
if (packagingType === 'own') {
if (isNaN(weight) || weight 5) {
alert("Warning: Flat rate satchels generally have a 5kg weight limit. Extra charges may apply.");
// Add simplified over-weight charge
basePrice += (weight – 5) * 5.50;
}
} else {
// Own Packaging Logic (Zone based approximated to National Average)
// Using "If It Packs, It Posts" style tiers based on size/weight
if (chargeableWeight <= 0.5) {
basePrice = rates.small;
} else if (chargeableWeight <= 1.0) {
basePrice = rates.medium;
} else if (chargeableWeight <= 3.0) {
basePrice = rates.large;
} else if (chargeableWeight 5kg
// Base 5kg rate + approx $0.85 to $2.00 per extra kg depending on distance
// We will use a conservative national estimator of $1.50 per extra kg
basePrice = rates.xl + ((chargeableWeight – 5) * 1.50);
}
}
// 6. Service Type Adjustment
// Express is typically ~30-40% more or a fixed upgrade fee.
// We will use a multiplier for estimation.
if (serviceType === 'express') {
basePrice = basePrice * 1.35;
}
// 7. Extra Cover (Insurance) Logic
// Usually $0 for first $100, then ~$2.50 per $100 (or part thereof)
var insuranceCost = 0;
if (itemValue > 100) {
var valueToInsure = itemValue – 100;
var units = Math.ceil(valueToInsure / 100);
insuranceCost = units * 2.50;
}
// 8. Total Calculation
var totalCost = basePrice + insuranceCost;
// 9. Display Results
document.getElementById('res-cubic').innerText = cubicWeight.toFixed(2) + " kg";
document.getElementById('res-chargeable').innerText = chargeableWeight.toFixed(2) + " kg";
document.getElementById('res-base').innerText = "$" + basePrice.toFixed(2);
document.getElementById('res-insurance').innerText = "$" + insuranceCost.toFixed(2);
document.getElementById('res-total').innerText = "$" + totalCost.toFixed(2);
document.getElementById('result-area').style.display = 'block';
}
Understanding Australia Post Parcel Rates
Sending parcels within Australia can sometimes be confusing due to the various factors that influence the final cost. Whether you are an eCommerce business owner sending daily orders or an individual sending a gift to a relative interstate, understanding how Australia Post calculates shipping rates can help you save money and choose the right service.
1. Actual Weight vs. Cubic Weight
One of the most critical concepts in logistics is the difference between actual weight and cubic weight (also known as volumetric weight). Australia Post, like most carriers, charges based on whichever is greater.
Actual Weight: The dead weight of the parcel as shown on a scale (e.g., 2kg).
Cubic Weight: A calculation based on the space the parcel occupies in the delivery van or plane. The formula generally used for domestic parcels is: Length (m) × Width (m) × Height (m) × 250.
For example, a large box filled with pillows might only weigh 1kg (actual), but its cubic weight could be 10kg due to its size. You would be charged for the 10kg rate.
2. Flat Rate Satchels vs. Own Packaging
Australia Post offers an "If It Packs, It Posts" flat rate system for items weighing up to 5kg. This is often the most economical choice for heavy but small items.
Small Satchel: Ideal for small electronics or accessories.
Medium Satchel: Good for books or standard clothing items.
Large Satchel: Suitable for shoes or larger clothing orders.
Extra Large Satchel: Best for bulky items up to 5kg.
If you use your own packaging, the price is determined by the size and weight tier your parcel falls into (Small, Medium, Large, or Extra Large equivalent).
3. Express Post vs. Regular Post
Regular Parcel Post is cost-effective and includes tracking. Delivery times vary based on zones (Metro to Metro is usually faster than Country to Country).
Express Post guarantees next business day delivery within the defined Express Post network (covering 80% of Australian business addresses, private boxes, and post offices). This service commands a premium price, usually calculated as an uplift on the standard rate.
4. Extra Cover (Insurance)
Most standard Australia Post services come with $100 of included compensation for loss or damage. If you are shipping items valued over $100, you should purchase "Extra Cover."
The cost is generally calculated as a fee for every $100 of value (or part thereof) above the initial included $100. Our calculator above helps you estimate this surcharge automatically.
Tips for Reducing Postage Costs
Optimise Packaging: Use the smallest box possible to reduce cubic weight charges.
Use Prepaid Satchels: If your item is heavy (dense) but small, prepaid satchels cap the price at the size rate rather than the weight rate (up to 5kg).
Bulk Discounts: If you are a business, sign up for a MyPost Business account to access tiered savings based on your volume.