USPS Ground Advantage™ (2-5 days)
Priority Mail® (1-3 days)
Priority Mail Express® (Next Day)
Media Mail (Books/Media Only – Slow)
Zone 1 (Local – within 50 miles)
Zone 2 (51-150 miles)
Zone 3 (151-300 miles)
Zone 4 (301-600 miles)
Zone 5 (601-1000 miles)
Zone 6 (1001-1400 miles)
Zone 7 (1401-1800 miles)
Zone 8 (1801+ miles)
Zone 9 (Freely Associated States)
Estimated Retail Postage
$0.00
How to Use This USPS Rate Calculator
Calculating shipping costs accurately is essential for ecommerce businesses and individuals alike. This tool estimates the retail postage rates for domestic US shipments based on the weight of your package, the distance it needs to travel (Zones), and the speed of service required.
Note: This calculator provides estimates based on standard retail pricing tiers. Commercial Base Pricing (used by shipping software like Stamps.com or Pirate Ship) is typically lower.
Understanding the Inputs
Mail Service Class:
USPS Ground Advantage™: The most affordable option for packages up to 70 lbs. Delivery usually takes 2-5 business days.
Priority Mail®: Faster delivery (1-3 business days) with flat rate options available, though this calculator focuses on weight-based zones.
Priority Mail Express®: The fastest domestic service, offering overnight delivery to most U.S. addresses.
Media Mail: A cost-effective way to send books and educational materials, but strictly limited to specific content types.
Destination Zone: USPS divides the United States into "Zones" based on the distance from the origin zip code. Zone 1 is local, while Zone 8 represents the furthest distance within the continental US.
Package Weight: Postage is rounded up to the next pound for Priority and Express mail. Ground Advantage uses ounce-based pricing for packages under 1 lb.
Factors That Influence Your Shipping Rate
The final cost of your label is determined by what is known as "dimensional weight" in addition to actual weight. If you are shipping a large, lightweight box, USPS may charge you based on the volume of the box rather than the scale weight. This calculator uses standard scale weight logic.
Dimensional Weight Rule
For packages larger than 1 cubic foot (1,728 cubic inches), USPS applies a dimensional weight divisor. If your package is large but light, the cost will increase significantly, especially for Zones 5-9.
Tips for Saving on Postage
To reduce your shipping costs, consider the following strategies:
Use Flat Rate Boxes: If your item is heavy (over 2-3 lbs) and fits in a Priority Mail Flat Rate box, that is often cheaper than Zone-based pricing.
Buy Labels Online: Purchasing postage through third-party platforms often unlocks "Commercial Pricing," which can be up to 40% cheaper than the retail rates shown at the Post Office counter.
Keep it Under 1 lb: If you can keep your package under 16 ounces, First-Class (now part of Ground Advantage) is significantly cheaper than Priority Mail.
function calculatePostage() {
// 1. Get Inputs
var service = document.getElementById('serviceType').value;
var zone = parseInt(document.getElementById('shippingZone').value);
var lbs = parseFloat(document.getElementById('weightLbs').value) || 0;
var oz = parseFloat(document.getElementById('weightOz').value) || 0;
var errorDiv = document.getElementById('errorDisplay');
var resultBox = document.getElementById('resultBox');
var priceDisplay = document.getElementById('resultPrice');
var summaryDisplay = document.getElementById('resultSummary');
// Reset display
errorDiv.style.display = 'none';
resultBox.style.display = 'none';
// 2. Validation
if (lbs === 0 && oz === 0) {
errorDiv.textContent = "Please enter a valid weight (Lbs or Oz).";
errorDiv.style.display = 'block';
return;
}
// Calculate total weight in Pounds for heavy logic, and Ounces for light logic
var totalWeightLbs = lbs + (oz / 16);
var totalWeightOz = (lbs * 16) + oz;
// Rounding logic: USPS generally rounds up to the nearest pound for Priority/Express
// For Ground under 1lb, it uses specific ounce tiers.
var ratedWeight = Math.ceil(totalWeightLbs);
if (ratedWeight === 0) ratedWeight = 1; // Minimum 1 lb billing for most services unless specified
if (totalWeightLbs > 70) {
errorDiv.textContent = "USPS limit is 70 lbs. Please split your shipment.";
errorDiv.style.display = 'block';
return;
}
// 3. Rate Calculation Logic (Simulated 2024 Retail Pricing Structures)
// Note: These are estimation formulas designed to mimic the curve of Zone/Weight pricing
var finalPrice = 0;
var deliveryTime = "";
if (service === 'media') {
// Media mail is not zone based, strictly weight based
// Base $4.13 for first lb + roughly $0.75 per additional lb
finalPrice = 4.13 + ((ratedWeight – 1) * 0.75);
deliveryTime = "2-8 Business Days";
}
else if (service === 'ground') {
deliveryTime = "2-5 Business Days";
if (totalWeightOz < 16) {
// Light packages (under 1 lb) – Zone based but cheaper
// Base approx $5.00 to $6.50 depending on zone/weight
var baseUnderLb = 4.75;
var zoneFactor = 0.20 * zone;
var weightFactor = 0.15 * totalWeightOz;
finalPrice = baseUnderLb + zoneFactor + weightFactor;
} else {
// Over 1 lb
// Base ~$8.00 + Zone multipliers
var baseGround = 7.50;
var weightCost = (ratedWeight – 1) * 1.50; // Cost per lb added
var zoneCost = zone * 0.85 * ratedWeight; // Zone impact increases with weight
finalPrice = baseGround + weightCost + zoneCost;
}
}
else if (service === 'priority') {
deliveryTime = "1-3 Business Days";
// Priority Mail Retail
// Base starts around $9.25 for Zone 1, 1lb
var basePriority = 9.00;
var weightMultiplier = 2.10; // Cost per additional lb
var zoneMultiplier = 1.15; // Zone impact
// Formula: Base + (Weight * WeightMult) + (Zone * ZoneMult * WeightFactor)
// Adjusted to prevent runaway costs on high zones
var pRate = basePriority + ((ratedWeight – 1) * weightMultiplier) + (zone * zoneMultiplier) + (ratedWeight * zone * 0.35);
finalPrice = pRate;
}
else if (service === 'express') {
deliveryTime = "Next Day to 2 Days";
// Express is expensive. Starts around $30.
var baseExpress = 30.45;
var weightMultiplierExp = 5.50;
var zoneMultiplierExp = 4.00;
finalPrice = baseExpress + ((ratedWeight – 1) * weightMultiplierExp) + (zone * 2.50) + (ratedWeight * zone * 0.50);
}
// 4. Formatting and Display
finalPrice = Math.round(finalPrice * 100) / 100; // Round to 2 decimals
priceDisplay.innerHTML = "$" + finalPrice.toFixed(2);
var zoneText = "Zone " + zone;
var weightText = "";
if (totalWeightOz < 16) {
weightText = Math.round(totalWeightOz * 10) / 10 + " oz";
} else {
weightText = ratedWeight + " lbs (Rated)";
}
summaryDisplay.innerHTML = `
Service: ${document.getElementById('serviceType').options[document.getElementById('serviceType').selectedIndex].text}
Weight: ${weightText}
Destination: ${zoneText}
Est. Delivery: ${deliveryTime}
`;
resultBox.style.display = 'block';
}