Standard Letter (Stamped)
Standard Letter (Metered)
Postcard
Large Envelope (Flat)
Choose the physical format of your mail piece.
Enter precise weight. Max 3.5 oz for letters, 13 oz for flats.
Mail Class:–
Base Rate (1st oz):–
Additional Ounces:–
Total Postage Cost:–
function calculatePostage() {
var mailType = document.getElementById('mailType').value;
var weightInput = document.getElementById('weightOz').value;
var resultArea = document.getElementById('result-area');
var errorDisplay = document.getElementById('error-display');
// Reset display
errorDisplay.style.display = 'none';
resultArea.style.display = 'none';
// Validation
if (weightInput === "" || isNaN(weightInput) || parseFloat(weightInput) 3.5) {
// Auto-upgrade logic or error? Usually upgrades to Flat.
// For this calculator, we will switch logic to Flat but warn user,
// or just error out. Let's treat as Large Envelope if heavy.
// However, strictly, let's stick to the selected type logic for clarity
// or output an error saying "Too heavy for letter".
errorDisplay.innerText = "Standard letters cannot exceed 3.5 oz. Please select 'Large Envelope (Flat)'.";
errorDisplay.style.display = 'block';
return;
}
basePrice = 0.60;
className = "First-Class Mail Letter (Stamped)";
} else if (mailType === 'letter_metered') {
if (weight > 3.5) {
errorDisplay.innerText = "Standard letters cannot exceed 3.5 oz. Please select 'Large Envelope (Flat)'.";
errorDisplay.style.display = 'block';
return;
}
basePrice = 0.57;
className = "First-Class Mail Letter (Metered)";
} else if (mailType === 'postcard') {
// Postcards have strict dimension limits, usually up to 4.25″ x 6″.
// Weight is negligible but theoretically defined.
basePrice = 0.44;
addPrice = 0; // Postcards are a flat rate
className = "First-Class Postcard";
if (weight > 1) { // Assuming standard card stock
// Just a warning in logic, but technically price doesn't scale by oz for postcards
}
} else if (mailType === 'flat') {
if (weight > 13) {
errorDisplay.innerText = "Large Envelopes cannot exceed 13 oz. This qualifies as Priority Mail (Parcel).";
errorDisplay.style.display = 'block';
return;
}
basePrice = 1.20;
className = "First-Class Large Envelope (Flat)";
}
// Calculation Logic
// Price is Base + (Ceiling(Weight) – 1) * AddPrice
// Example: 1.1 oz counts as 2 oz.
var billableWeight = Math.ceil(weight);
if (billableWeight < 1) billableWeight = 1;
if (mailType === 'postcard') {
total = basePrice;
addOuncesCost = 0;
} else {
// First ounce is basePrice
// Remaining ounces
var additionalOunces = billableWeight – 1;
addOuncesCost = additionalOunces * addPrice;
total = basePrice + addOuncesCost;
}
// Display Results
document.getElementById('res-class').innerText = className;
document.getElementById('res-base').innerText = "$" + basePrice.toFixed(2);
if (mailType === 'postcard') {
document.getElementById('res-add').innerText = "N/A";
} else {
document.getElementById('res-add').innerText = (billableWeight – 1) + " x $" + addPrice.toFixed(2) + " = $" + addOuncesCost.toFixed(2);
}
document.getElementById('res-total').innerText = "$" + total.toFixed(2);
resultArea.style.display = 'block';
}
Understanding 2022 US Postage Rates
The United States Postal Service (USPS) implemented significant rate changes in 2022, specifically on July 10, 2022. This calculator is designed to reflect those specific rate hikes, known as the "Market Dominant" price adjustment.
Key Rate Changes (July 2022)
If you are looking to mail items using 2022 stamps or calculate costs for that fiscal period, here are the critical numbers:
Mail Type
Jan 2022 Rate
July 2022 Rate (Final)
First-Class Letter (1 oz)
$0.58
$0.60
Additional Ounce (Letters)
$0.20
$0.24
Metered Letter (1 oz)
$0.53
$0.57
Postcard
$0.40
$0.44
Large Envelope / Flat (1 oz)
$1.16
$1.20
How to Use This Calculator
Select Mail Type: Choose whether you are sending a standard letter, a postcard, or a large envelope (flat).
Enter Weight: Weigh your item on a scale. Enter the weight in ounces. Note that postage is calculated by the ounce, meaning 1.1 oz is charged the same as 2.0 oz.
Analyze Result: The calculator provides the base cost for the first ounce plus the cost for any additional ounces.
Definition of Mail Types
Standard Letter: Must be rectangular and weigh less than 3.5 ounces. If it weighs more, it must be mailed as a Large Envelope.
Large Envelope (Flat): Must be rectangular, flexible, and uniformly thick. The maximum weight is 13 ounces. Items heavier than 13 oz must be sent as Priority Mail.
Forever Stamps: If you purchased Forever Stamps prior to July 2022 at the lower rate ($0.58), they were still valid for the 1-ounce rate ($0.60) after the price increase without needing additional postage.
Why Did Rates Increase in 2022?
The 2022 postage rate increases were part of the "Delivering for America" 10-year plan aimed at achieving financial stability for the USPS. The prices increased by approximately 6.5% in July 2022 to account for inflation and operating costs.