First Class Mail vs Priority Mail: Cost & Speed Comparison (2025)
Quick Answer
- • Light items under 13 oz? → First Class Mail (cheaper)
- • Need speed or insurance? → Priority Mail
- • Over 13 oz? → Must use Priority Mail
First Class Mail and Priority Mail are USPS's most popular services for letters and packages. They're often compared when deciding between First Class vs Priority Mail for 2025 shipping rates and delivery times, especially now that USPS Ground Advantage has replaced First-Class Package Service. The main differences are weight limits, delivery speed, and cost. Here's how to choose the right one for your shipment.
USPS Delivery Time Estimator
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| Feature | First Class Mail | Priority Mail |
|---|---|---|
| Delivery Time | 2-5 business days | 1-3 business days |
| Weight Limit (Letters) | 3.5 oz | N/A |
| Weight Limit (Packages) | Flats up to 13 oz* | 70 lbs |
| Starting Price | $0.78 (letter) | ~$9–$11 |
| Insurance Included | No | Up to $100 |
| Tracking | No for letters; included with Ground Advantage | Yes |
| Free Supplies | No | Yes |
| Flat Rate Options | No | Yes |
| Best For | Letters, flats, lightweight mail | Heavier packages, time-sensitive |
*First-Class Mail covers letters up to 3.5 oz and flats up to 13 oz. Most packages now ship via USPS Ground Advantage or Priority Mail.
When to Use First Class Mail
First Class Mail is the most economical option for lightweight items when speed isn't critical.
Use First Class Mail For:
- ✅ Standard letters and cards
- ✅ Bills and invoices
- ✅ Documents under 3.5 oz
- ✅ Lightweight flats under First-Class Mail limits
- ✅ Non-urgent correspondence
- ✅ Budget-conscious shipping
Note: For packages, USPS now uses Ground Advantage (which replaced First-Class Package Service). Many people still search "first class package," but packages are typically shipped via Ground Advantage or Priority Mail.
First Class Limitations:
- • Letters cannot exceed 3.5 oz
- • Heavier items and most packages now use USPS Ground Advantage or Priority Mail
- • No insurance included
- • Letters don't include tracking
- • Delivery can take up to 5 days
When to Use Priority Mail
Priority Mail is the best choice when you need faster delivery, insurance, or are shipping heavier items.
Use Priority Mail For:
- ✅ Packages over 13 oz (required)
- ✅ Time-sensitive shipments
- ✅ Items needing insurance coverage
- ✅ Heavy items (flat rate boxes save money)
- ✅ Business shipments needing tracking
- ✅ Valuable items under $100
Priority Mail Benefits:
- • Free Boxes: Order free Priority Mail supplies from USPS
- • Flat Rate Pricing: Ship heavy items at a fixed cost
- • $100 Insurance: Included at no extra charge
- • Full Tracking: Detailed scan updates
- • Saturday Delivery: Included at no extra cost
2025 Pricing Comparison
| Item Type | First Class | Priority Mail |
|---|---|---|
| 1 oz letter | $0.78 | N/A |
| 4 oz package | ~$4.50 | ~$9.90 |
| 8 oz package | ~$5.50 | ~$9.90 |
| 13 oz package | ~$6.50 | ~$9.90 |
| 1 lb package | N/A (over limit) | ~$10.50 |
| Flat Rate Envelope | N/A | $10.40 |
| Small Flat Rate Box | N/A | $10.85 |
| Medium Flat Rate Box | N/A | $17.40 |
*Prices are approximate 2025 retail rates. Commercial rates are lower. Use our free USPS mailing cost calculator for real-time pricing.
Frequently Asked Questions
What's the difference between First Class and Priority Mail?
First Class Mail is cheaper but slower (2-5 days) and limited to 13 oz. Priority Mail is faster (1-3 days), includes $100 insurance, and handles packages up to 70 lbs. Choose First Class for light, non-urgent items and Priority Mail for heavier or time-sensitive packages.
How much does First Class Mail cost vs Priority Mail?
First-Class Mail letters start at $0.78 (2025), and USPS Ground Advantage packages start around $4.00. Priority Mail starts around $9–$11 for flat rate options. First-Class Mail is significantly cheaper for letters and flats under 13 oz.
What's the weight limit for First Class Mail?
First-Class Mail letters are limited to 3.5 oz and flats to 13 oz. For packages, USPS Ground Advantage (which replaced First-Class Package Service) handles items up to 70 lbs. Items over the First-Class Mail weight limits typically use Ground Advantage or Priority Mail.
Does First Class Mail include tracking?
First-Class Mail letters do NOT include tracking unless you add a service like Certified Mail. USPS Ground Advantage (which replaced First-Class Package Service) includes tracking for packages. Priority Mail includes tracking for all items.
Need to Send Important Documents?
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