*Rates are estimates based on typical USPS entry points (None/Origin). Destination entry discounts (DNDC/DSCF) are not applied in this basic calculation.
Understanding USPS Bulk Mail Rates
Bulk mail, officially known as USPS Marketing Mail or First-Class Mail Presort, allows businesses and non-profits to save significantly on postage by doing some of the work for the Post Office. By sorting your mail by zip code and meeting specific quantity minimums, you can qualify for rates far below the standard retail price of a stamp.
Minimum Quantity Requirements
To qualify for bulk mailing rates, you must meet these minimums per mailing:
Marketing Mail (Standard): 200 pieces or 50 lbs.
First-Class Presort: 500 pieces.
Mail Classes Explained
Choosing the right class affects both your delivery speed and your budget:
Feature
First-Class Presort
Marketing Mail
Delivery Time
1-3 Business Days (National)
3-10 Business Days (National)
Cost
Higher (Moderate Discount)
Lowest (Deep Discount)
Forwarding
Free Forwarding & Return
No Free Forwarding (Disposed)
Content
Bills, Invoices, Personal
Advertisements, Newsletters, Flyers
How Presort Levels Affect Price
The "Presort Level" refers to how finely you sort the mail before handing it to the USPS. The more you sort, the less the USPS has to do, and the lower your rate.
Mixed AADC: The most basic level. Mail is sorted by broad regions. This is the most expensive bulk rate.
AADC: Sorted by Area Distribution Center. Cheaper than mixed.
5-Digit: Sorted specifically by the 5-digit zip code. This requires a high density of addresses in specific areas but offers the lowest possible postage rate.
Weight Limits and Surcharges
For standard letters, the base price typically covers up to 3.5 ounces. For flats (large envelopes), the base price covers the first 4 ounces, with additional costs per ounce thereafter. If your marketing mail piece is heavy, ensure you calculate the weight correctly, as costs can shift from a "per piece" price to a combined "per piece + per pound" price.
Non-Profit Status
Authorized non-profit organizations (Form 3624) are eligible for Non-Profit USPS Marketing Mail rates. These are significantly lower than Commercial Marketing Mail rates, often saving an additional 30-40% off the commercial bulk price.
function calculatePostage() {
// 1. Get Elements
var mailClass = document.getElementById("mailClass").value;
var orgType = document.getElementById("organizationType").value;
var mailShape = document.getElementById("mailShape").value;
var sortLevel = document.getElementById("sortLevel").value;
var quantity = document.getElementById("mailQuantity").value;
var weight = document.getElementById("weightPerPiece").value;
var resultBox = document.getElementById("resultBox");
var errorBox = document.getElementById("errorBox");
// 2. Validate Inputs
if (!quantity || quantity <= 0) {
errorBox.style.display = "block";
errorBox.innerHTML = "Please enter a valid quantity of pieces.";
resultBox.style.display = "none";
return;
}
if (!weight || weight <= 0) {
errorBox.style.display = "block";
errorBox.innerHTML = "Please enter a valid weight per piece.";
resultBox.style.display = "none";
return;
}
// Parse numbers
var qtyNum = parseInt(quantity);
var weightNum = parseFloat(weight);
// Check Minimums
var minimumError = false;
if (mailClass === 'marketing' && qtyNum < 200) {
minimumError = true;
errorBox.innerHTML = "Marketing Mail requires a minimum of 200 pieces.";
} else if (mailClass === 'first_class' && qtyNum 1) {
// Approx +$0.24 per additional oz for retail
retailRate += (Math.ceil(weightNum) – 1) * 0.24;
}
// Determine Bulk Rate
var ratePerPiece = 0;
// — Logic Selection —
// FIRST CLASS PRESORT
if (mailClass === 'first_class') {
if (orgType === 'nonprofit') {
// First class doesn't have a separate "Non-Profit" rate schedule like Marketing Mail.
// It uses the same Commmercial rates generally, but we'll stick to standard logic.
// We will treat it same as commercial first class.
}
if (mailShape === 'postcard') {
// Postcard Rates: Mixed: 0.404, AADC: 0.386, 5-Digit: 0.357
if (sortLevel === 'mixed') ratePerPiece = 0.404;
else if (sortLevel === 'aadc') ratePerPiece = 0.386;
else if (sortLevel === '5digit') ratePerPiece = 0.357;
}
else if (mailShape === 'letter') {
// Letter Rates (Auto): Mixed: 0.561, AADC: 0.537, 5-Digit: 0.498
// Weight limit 3.5oz included in base
if (weightNum > 3.5) {
errorBox.style.display = "block";
errorBox.innerHTML = "First-Class Automation Letters cannot exceed 3.5 oz.";
resultBox.style.display = "none";
return;
}
if (sortLevel === 'mixed') ratePerPiece = 0.561;
else if (sortLevel === 'aadc') ratePerPiece = 0.537;
else if (sortLevel === '5digit') ratePerPiece = 0.498;
}
else if (mailShape === 'flat') {
// Flat Rates (Auto): Mixed: 1.13, AADC: 1.05, 5-Digit: 0.86
// + weight fees above 1oz
var baseFlat = 0;
if (sortLevel === 'mixed') baseFlat = 1.13;
else if (sortLevel === 'aadc') baseFlat = 1.05;
else if (sortLevel === '5digit') baseFlat = 0.86;
// Add weight per oz above 1 (approx 0.24 for presort)
if (weightNum > 1) {
baseFlat += (Math.ceil(weightNum) – 1) * 0.24;
}
ratePerPiece = baseFlat;
}
}
// MARKETING MAIL (STANDARD)
else if (mailClass === 'marketing') {
if (mailShape === 'postcard') {
// Marketing mail doesn't strictly have "postcards", they are treated as letters.
// We will force logic to letter rate.
mailShape = 'letter';
}
// Check max weight for letter rate (3.5oz breakpoint generally)
// If heavier, logic gets complex (piece + pound).
// Simplified: If > 4oz, warn user this calc is for lightweight only to ensure accuracy.
if (weightNum > 4 && mailShape === 'letter') {
errorBox.style.display = "block";
errorBox.innerHTML = "Marketing Letters over 4oz are calculated as Flats or Parcels. Please select 'Flat' or reduce weight.";
resultBox.style.display = "none";
return;
}
if (orgType === 'commercial') {
if (mailShape === 'letter') {
// Comm Letter: Mixed: 0.381, AADC: 0.361, 5-Digit: 0.326
if (sortLevel === 'mixed') ratePerPiece = 0.381;
else if (sortLevel === 'aadc') ratePerPiece = 0.361;
else if (sortLevel === '5digit') ratePerPiece = 0.326;
}
else if (mailShape === 'flat') {
// Comm Flat: Mixed: 0.99, AADC: 0.89, 5-Digit: 0.68
// Base rate covers up to 4oz usually.
if (sortLevel === 'mixed') ratePerPiece = 0.99;
else if (sortLevel === 'aadc') ratePerPiece = 0.89;
else if (sortLevel === '5digit') ratePerPiece = 0.68;
// Simple surcharge logic for demo if > 4oz
if (weightNum > 4) {
ratePerPiece += (weightNum – 4) * 0.15; // approximate pound rate allocation
}
}
}
else if (orgType === 'nonprofit') {
if (mailShape === 'letter') {
// NP Letter: Mixed: 0.230, AADC: 0.210, 5-Digit: 0.165
if (sortLevel === 'mixed') ratePerPiece = 0.230;
else if (sortLevel === 'aadc') ratePerPiece = 0.210;
else if (sortLevel === '5digit') ratePerPiece = 0.165;
}
else if (mailShape === 'flat') {
// NP Flat: Mixed: 0.76, AADC: 0.65, 5-Digit: 0.44
if (sortLevel === 'mixed') ratePerPiece = 0.76;
else if (sortLevel === 'aadc') ratePerPiece = 0.65;
else if (sortLevel === '5digit') ratePerPiece = 0.44;
if (weightNum > 4) {
ratePerPiece += (weightNum – 4) * 0.15;
}
}
}
}
// 4. Calculate Totals
var totalBulkCost = ratePerPiece * qtyNum;
var totalRetailCost = retailRate * qtyNum;
var totalSavings = totalRetailCost – totalBulkCost;
// 5. Display Results
errorBox.style.display = "none";
resultBox.style.display = "block";
document.getElementById("totalCostDisplay").innerHTML = "$" + totalBulkCost.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("ratePerPieceDisplay").innerHTML = "$" + ratePerPiece.toFixed(3);
document.getElementById("retailCostDisplay").innerHTML = "$" + totalRetailCost.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("savingsDisplay").innerHTML = "$" + totalSavings.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
}