Free planning tool
A lead time calculator finds your delivery date by adding the lead time to a start date, or your order-by date by subtracting the lead time from a need-by date. Enter a date, a lead time in days or weeks, and choose calendar or business days to get your answer instantly.
Calendar counts all 7 days a week. Business counts 5 days a week (excludes Saturday & Sunday).
Date-based lead time is the simplest and most common planning method. You add or subtract a known lead time to find the date you need.
Delivery Date = Start Date + Lead Time
Use this when you know the start date (order date, kickoff date, request date) and you want to know when the output will be ready (delivery, completion, arrival).
Order-By Date = Need-By Date − Lead Time
Use this when you know the date you must have something by and you want the latest date you can start or place the order.
Lead time shows up everywhere — especially when dates and commitments matter.
Calendar days count every day. Business days exclude weekends. If your lead time depends on holidays, adjust the result date or use a dedicated holiday calendar.
Start date: March 1. Lead time: 14 days. Output: Delivery date is March 15 (calendar days).
Need-by date: April 30. Lead time: 3 weeks. Output: Order-by date is three weeks earlier (calendar weeks).
Start date: Monday. Lead time: 5 business days. Output: Delivery date is the following Monday (weekends excluded).
Tip: If you want a buffer, add extra days to the lead time. Many teams keep a safety buffer to protect customer commitments.
Real-world lead times, record builds, and famous waits — every fact sourced.
Apple announced the original iPhone on January 9, 2007, but it didn't go on sale until June 29, 2007 — a 171-day wait between reveal and delivery.
Steve Jobs unveiled it at Macworld with no finished product ready to ship, giving Apple under six months to finalize it. Source: Wikipedia
Tesla unveiled the Cybertruck on November 21, 2019, but the first customer deliveries didn't happen until November 30, 2023 — a lead time of just over four years.
Production slipped roughly two years past Tesla's original late-2021 target before the Austin delivery event. Source: NPR
The James Webb Space Telescope launched on December 25, 2021 — about 25 years after initial designs began in 1996.
Early plans targeted a 2007 launch, but redesigns, cost growth, and testing pushed it back nearly 15 years. Source: Wikipedia
During the global chip shortage, average semiconductor lead times hit a record 27.1 weeks in May 2022 — over six months of waiting.
Lead times had already hit then-record highs of 18 weeks in June 2021 and kept climbing for nearly a year, per Susquehanna Financial Group's tracking. Source: KED Global
US power transformer lead times ballooned from about 50 weeks in 2021 to an average of 120 weeks by 2024 — with large units taking 80 to 210 weeks.
Some grid transformers ordered today arrive roughly four years later, per Wood Mackenzie's 2024 analysis. Source: Wood Mackenzie
Fabricating a single semiconductor chip takes about 12 weeks — and up to 14–20 weeks for advanced processes — before roughly 6 more weeks of assembly, test, and packaging.
The Semiconductor Industry Association puts total order-to-delivery lead time at up to 26 weeks even in normal conditions. Source: Semiconductor Industry Association
After Pan Am ordered 25 Boeing 747s in April 1966, Boeing had just 28 months to design the jumbo jet — rolling it out on September 30, 1968.
That was about two-thirds the normal development time, and the breakneck-pace team earned the nickname 'The Incredibles.' Source: Wikipedia
The Empire State Building was built in just 410 days: the first steel column was set on March 17, 1930, and the skyscraper officially opened on May 1, 1931.
Crews erected the 102-story tower's steel frame at a pace of up to four and a half stories per week. Source: History.com
In November 1942, the WWII Liberty ship SS Robert E. Peary was assembled in a record 4 days and 15.5 hours, from keel laying to launch.
Guinness World Records credits extensive prefabrication for the fastest-ever ship build — part of a wartime race to outbuild U-boat sinkings. Source: Guinness World Records
When the container ship Ever Given wedged across the Suez Canal in March 2021, it blocked the waterway for six days — holding up an estimated $9.6 billion of trade per day.
Lloyd's List estimated roughly $400 million of goods delayed per hour while the ship was stuck. Source: gCaptain
Shipping a full ocean container from Shanghai to Los Angeles typically takes about 27 to 36 days in transit.
Smaller less-than-container-load shipments on the same route run even longer, at roughly 29 to 41 days, per freight marketplace Freightos. Source: Freightos
Airbus and Boeing had a combined backlog of 16,683 unfilled aircraft orders as of April 2026 — roughly 12 years of work at current production rates.
Order a new jet today and, on average, you're queuing behind more than a decade of earlier customers. Source: Aerospace Global News
The Hermès Birkin bag was once reputed to have a waiting list of up to six years — and even today a first-time customer can't simply walk in and buy one.
Hermès scrapped the formal waitlist in 2010; buyers typically must first build a purchase history of other goods. Source: Wikipedia
US retailers often begin planning for the winter holidays in January and typically finalize the bulk of their Christmas orders by the end of June — about six months ahead.
Ocean-shipped holiday goods start arriving at US warehouses by mid-summer, which is why ports peak months before December. Source: Fortune / AP
Boeing's 787 Dreamliner was due to reach its launch customer in 2008, but the first delivery didn't happen until September 25, 2011 — about three years late.
Supply chain problems, fastener shortages, and software issues repeatedly pushed back the carbon-composite jet's debut. Source: Wikipedia
What is lead time?
Lead time is the total time between when a process starts and when it is completed. In ordering and planning, it often means the time from an order date to a delivery date. The ASCM (formerly APICS) Supply Chain Dictionary defines it as the span between the recognition of a need and its fulfillment.
Should I use business days or calendar days?
Use calendar days when commitments are based on total elapsed time. Use business days when work only happens on weekdays. Some organizations also exclude holidays, which vary by company and location.
What does “Include the start date as day 1” mean?
Some teams count the start date as the first day of lead time. Others start counting the next day. If you need that convention, add one day (or one business day) to match your organization’s definition.
Can I share a calculation?
Yes. You can copy the URL after you calculate to share your setup.
Jump straight to a pre-calculated lead time. Each page shows today’s resulting date in calendar and business days.
New to lead time? Read our guide: How to Calculate Lead Time — formula, examples, and business-day rules.
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