# Lead Time Calculator

URL: https://speedycalculator.com/calculators/everyday-life/lead-time/
Last updated: 2026-10-25

> The lead time calculator adds up manufacturing lead time (pre-processing, processing and post-processing) or supply-chain lead time (supply delay plus reorder delay) and gives the expected delivery date from an order date.

## Inputs

- Lead time type
- Pre-processing time (days)
- Processing time (days)
- Post-processing / shipping time (days)
- Supply delay (days)
- Reorder delay (days)
- Order date
- Count
- Daily usage (for reorder point)

## Results

- Lead time
- Expected delivery date
- Reorder point (lead time × daily usage)

## Formula

```
Manufacturing lead time = pre-processing + processing + post-processing
Supply chain lead time = supply delay + reorder delay
Delivery date = order date + lead time (calendar or working days)
```

## Explanation

Lead time is the total time from a customer's order (or your purchase order) until the goods are delivered. It includes waiting, production and shipping. Knowing it helps set reorder points – the stock level at which to reorder so you don't run out.

### How to use the Lead Time Calculator

- **Lead time type**
- **Pre-processing time**
- **Processing time**
- **Post-processing / shipping time**
- **Supply delay**
- **Reorder delay**
- **Order date**
- **Count**
- **Daily usage (for reorder point)**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Choose the type of lead time, enter its parts in days, and the order date and whether to count working days only.

### Tips

- Track a typical week before planning – real figures beat estimates.
- Break big tasks into smaller pieces and plan buffer time for interruptions.
- Re-run the numbers when your inputs change so plans stay realistic.
- Use results as a guide for decisions, not as a precise prediction.

### Common mistakes to avoid

- Counting calendar days when the deadline is in working days (or the reverse).
- Forgetting breaks, setup and handover time.
- Assuming every day is as productive as your best day.

### Inputs explained

FieldWhat to enterLead time typeChoose one: Manufacturing, Supply chainPre-processing timeIn daysProcessing timeIn daysPost-processing / shipping timeIn daysSupply delayIn daysReorder delayIn daysOrder dateA dateCountChoose one: Calendar days, Working days (Mon–Fri)Daily usage (for reorder point)A number

### Example values

How the main result changes when **Pre-processing time** changes and everything else stays at the example values above:

Pre-processing time (days)Lead time (days)191.59.52102.510.5311412

## Worked example

Inputs — Lead time type: Manufacturing; Pre-processing time: 2 days; Processing time: 5 days; Post-processing / shipping time: 3 days; Supply delay: 7 days; Reorder delay: 3 days; Order date: 2026-10-25; Count: Calendar days; Daily usage (for reorder point): 20.

Results — **Lead time = 10 days**; Expected delivery date = Wed, November 4, 2026; Reorder point (lead time × daily usage) = 200.

## FAQ

**What is the difference between lead time and cycle time?**
Lead time runs from order to delivery; cycle time is only the time spent actively working on a unit.

**How do I calculate a reorder point?**
Lead time × average daily usage, plus safety stock for variability.

**How can I shorten lead time?**
Reduce waiting between steps, keep key materials in stock and choose closer suppliers.

**What formula does the Lead Time Calculator use?**
Manufacturing lead time = pre-processing + processing + post-processing.