Lead Time Calculator Working Days
Calculate lead time on a working-day schedule
Use this version when weekday operations matter more than raw calendar elapsed time, especially for planning around staff availability and business-hour workflows.
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Enter values on the left to see your lead time breakdown and delivery estimate.
How to Calculate Working-Day Lead Time
Four steps to estimate your order-to-delivery timeline counting only Monday–Friday.
A working day is a unit of capacity, not a unit of time. It answers how many days of actual work a stage needs — which is why it is the right unit for planning and the wrong unit for promising. Turning working days into a delivery date requires knowing whose working week applies, and on a multi-stage order that is rarely a single answer.
This is where working-day estimates quietly drift. Each stage converts to elapsed time at its own rate, and applying one blanket five-day assumption across a chain that contains a six-day factory and a continuous port operation will be wrong at every stage, in both directions.
Worked example: one order, four different working weeks
An import passes through four stages, each run by a different organisation with a different working pattern. Each stage needs five working days of actual work. A planner assumes a standard five-day week throughout.
- Internal approval, 5-day week= 7 calendar days5 working days
- Factory production, 6-day week= ~6 calendar days5 working days
- Port and vessel, continuous= 5 calendar days5 working days
- Receiving and QC, 5-day week= 7 calendar days5 working days
- Blanket 5-day assumption= 28 calendar days20 working days
Twenty working days is correct as a measure of work. Converted stage by stage it is 25 calendar days; converted with a single five-day assumption it reads 28. Three days of phantom delay, all of it invented by the conversion rather than by anything in the supply chain. On longer chains the error grows, and because it is systematic rather than random it never averages out.
How working days convert to elapsed time
The multiplier depends entirely on the working pattern of the stage. Holidays subtract further on any pattern that observes them.
| Working pattern | Days worked per week | Multiplier | 20 working days = |
|---|---|---|---|
| Continuous / 24-7 operation | 7 | 1.00 | 20 calendar days |
| Six-day week | 6 | 1.17 | ~23 calendar days |
| Standard five-day week | 5 | 1.40 | 28 calendar days |
| Four-day week | 4 | 1.75 | 35 calendar days |
| Five-day week + 1 holiday | 5 | — | 29 calendar days |
| Five-day week + 1 week shutdown | 5 | — | 35 calendar days |
Arithmetic. The multiplier column is the factor to apply to a working-day figure to get elapsed calendar time, before holidays.
Getting working-day estimates right
Four things that decide whether a working-day figure converts cleanly into a date.
Convert per stage, not per order
Each organisation in the chain has its own working pattern, so each stage needs its own multiplier. A single blanket assumption applied across a mixed chain produces a systematic error rather than a random one — it always leans the same way, so it never cancels out over multiple orders.
Six-day manufacturing is common
Many factories work Saturdays, particularly in Asia. Applying a five-day assumption to a six-day supplier inflates the elapsed estimate by about 17%, which on a long production run is weeks of delay that does not exist. This is the rarer error of being too pessimistic, and it costs real inventory.
Transit does not observe your weekend
A vessel at sea, a container in a yard and an aircraft in the air all move on Saturdays. Transit legs convert at roughly one to one, so counting them in weekday-only terms adds days to every international estimate. Treat transit as calendar time and only the handling either side as working days.
Working days are for planning, dates are for promising
Working days describe capacity, which is what you need to schedule against. A customer, a project plan and a production slot all need a date. Do the conversion once, deliberately, with the right multiplier for each stage — and pass the date on rather than the count.
Related calculators
The Lead Time Calculator Working Days produces an estimate. Real lead times move with supplier capacity, congestion, customs and weather — confirm any committed date with your suppliers and logistics partners before acting on it.
Working-day lead time questions
Practical answers for teams that measure progress in working days instead of simple calendar days.