About Delivery Time Calculator

A free, independent tool for estimating USPS shipping times.

Our Mission

We built Delivery Time Calculator to solve a simple problem: people need a clear delivery date before they send packages, not after. Whether you're an online seller, a small business owner, or just sending a gift to family, knowing when your package will arrive helps you plan better.

Our calculator uses the service standards USPS publishes for the number of days. It also shows the USPS zone for your two ZIP codes, which sets the price, not the days.

We say where each number comes from and what it cannot tell you, and for a package already on its way, USPS tracking is the place to check.

Who Runs This Site

Hamdi Saidani

Founder and developer

I build websites and free online tools from Tunisia, and I have done it since 2020. My studio, Zaytouna Studio, works with food bloggers: a nine-person team that has built more than fifty food sites and driven over a hundred million Pinterest impressions.

This calculator started with a pattern in search data in late 2025: thousands of people asking every month how long USPS takes between two ZIP codes, and getting answers that were guesses. I built the first version in December 2025.

In September 2026 I rebuilt it on USPS's own published data, the Service Standards Directory and the Domestic Zone Chart, so the dates on this site come from published USPS sources, and anything that is our own estimate is marked "Estimate".

Zaytouna means olive tree in Arabic, the symbol of Tunisia.

The site is not run by a shipping company or by the Postal Service. If you spot a number that looks wrong, tell me through the contact page and I will correct it.

What We Stand For

USPS Data First

We use the official USPS service standards and zone chart, and we label anything that is our own estimate.

User-Focused

No sign-ups, no fees, no spam. Just enter your ZIP codes and get your estimate. Simple as that.

Always Free

Our calculator is 100% free to use. We believe shipping information should be accessible to everyone.

Clear About Limits

We clearly state our limitations. We're not USPS, and we tell you when estimates may vary.

Our Methodology

Our delivery estimates are based on a combination of:

USPS Service Standards Directory - the number of days USPS publishes for each pair of 3-digit ZIP Code areas in the directory and each main mail class except Priority Mail Express (edition of October 1, 2026, from postalpro.usps.com), plus the 5-digit ZIP codes USPS lists as exceptions
USPS Domestic Zone Chart - the zone we show next to your ZIP codes (chart effective September 1, 2026). The zone sets the price, not the days
USPS Delivery Days - dates are counted the way USPS's own delivery-date tool counts them:
- holidays never count,
- Sundays count except the Sunday right after a Saturday mailing (mail dropped off the day before a holiday may skip Sundays too),
- and a result that lands on a Sunday or holiday moves to the next delivery day
Published Ranges Where the Directory Has No Column - Priority Mail Express is not in the USPS service standards directory, so it is shown as the 1-3 days USPS publishes; USPS gives the exact guaranteed date for a ZIP pair in its Service Commitments tool and at purchase

Each result is labeled "USPS standard" (from the USPS service standards directory, or for Priority Mail Express, the 1-3 days USPS publishes) or "Estimate" (our own calculation), so you can see how firm each number is.

The ship-by tool marks Priority Mail Express "Estimate" because it has to plan with one number from that range.

Important Disclaimer

We are NOT affiliated with, endorsed by, or connected to the United States Postal Service (USPS) in any way.

This is an independent tool that provides estimates based on publicly available USPS service standards. Our estimates are for planning purposes only and should not be considered guarantees.

For official shipping, tracking, and customer service, please visit usps.com.

How Our Calculator Works

1
Enter ZIP Codes and Date
Enter the ZIP code you mail from, the ZIP code it goes to, and the mailing date (today unless you pick another day).
2
Look Up the Zone
We look up the official USPS zone between your two ZIP Codes, which affects pricing.
3
Apply Service Standards
We apply official USPS delivery standards for each mail class to estimate arrival dates.
4
Count the Days
We count days the way USPS's own delivery-date tool counts them:
- holidays never count,
- Sundays count except the Sunday right after a Saturday mailing (mail dropped off the day before a holiday may skip Sundays too),
- and a result that lands on a Sunday or holiday moves to the next delivery day because regular mail is not delivered then.

Have Questions?

We're here to help. If you have questions about our calculator or suggestions for improvement, please reach out.