Wheel Throwing Time Calculator
The wheel time for a batch and a realistic calendar including drying, bisque and glaze firing.
The wheel is the fast part. Twenty bowls at 15 minutes to throw and 8 to trim is 7.7 hours of work, but the batch also needs a day or two to reach leather hard before it can be trimmed, and one to two weeks to dry fully before a bisque firing, with a firing and a cool either side. This calculator gives the wheel hours per stage and a calendar that shows what the batch actually costs in elapsed time rather than only in working time.
At a glance
- What you enter
- Pieces in the batch, Throwing time per piece, Trimming time per piece, Finishing and glazing time per piece, Failure and seconds allowance, Days to reach leather hard, Days to dry fully before a bisque, Days per firing including the cool, Pieces that dry in one day, Studio hours a week
- What you get
- Working hours for the batch, Throwing hours, Trimming hours, Finishing and glazing hours, Working hours per piece, Working hours per piece that survives, Days to leather hard for the whole batch, Days to dry fully for the whole batch, Elapsed days from throwing to finished, Lead time in weeks, Working days the batch takes, Days that are waiting rather than working, Share of the calendar that is work, Pieces made per studio hour, Studio sessions the batch takes
- Formula shown
- Yes, every step, right below your results.
- Cost and privacy
- Free, no account needed, and nothing you type is stored.
See worked examples ↓ Read the FAQ ↓ Share this calculator ↓
Results are estimates for general information only, always verify with a professional or official source before acting on them.
How to use the Wheel Throwing Time Calculator
- 1 Enter Pieces in the batch, The number of pieces you intend to make, before failures.
- 2 Enter Throwing time per piece (min), A simple bowl takes 10 to 20 minutes, a mug with a handle 12 to 25, a lidded jar 25 to 45.
- 3 Enter Trimming time per piece (min), Five to ten minutes on a simple bowl, longer with a foot ring or a fitted lid.
- 4 Enter Finishing and glazing time per piece (min), Waxing, dipping or brushing, wiping the base back and cleaning up. Five to fifteen minutes.
- 5 Enter Failure and seconds allowance (%), Ten percent is optimistic on a settled form, twenty is honest on a new one.
- 6 Enter Days to reach leather hard (days), The piece has to be firm enough to trim without deforming. One to three days is typical.
- 7 Enter Days to dry fully before a bisque (days), One to two weeks is typical. Thick forms and cold damp studios take longer.
- 8 Enter Days per firing including the cool (days), A bisque and a glaze firing each take a day to fire and cool to a temperature where the kiln can be opened. Two days each is a common planning figure.
- 9 Enter Pieces that dry in one day (pieces), How many pieces reach leather hard in a day in your studio. Twenty mugs in a warm room with air moving is a reasonable batch.
- 10 Enter Studio hours a week (h), Used to convert the total hours into working weeks.
- 11 Press Calculate. You get Working hours for the batch, Throwing hours, Trimming hours, Finishing and glazing hours, Working hours per piece, Working hours per piece that survives, Days to leather hard for the whole batch, Days to dry fully for the whole batch, Elapsed days from throwing to finished, Lead time in weeks, Working days the batch takes, Days that are waiting rather than working, Share of the calendar that is work, Pieces made per studio hour, Studio sessions the batch takes, and every intermediate step stays visible under "How is this calculated?"
- 12 Change one number at a time to see what moves the result, that is usually the most useful thing a calculator can tell you.
Worked examples
Real numbers run through this calculator. Open any example to load it into the form above and change it.
Twenty bowls
Fifteen minutes to throw and eight to trim, with a 12 percent failure allowance.
You enter
- Pieces in the batch
- 20
- Throwing time per piece
- 15 min
- Trimming time per piece
- 8 min
- Finishing and glazing time per piece
- 10 min
- Failure and seconds allowance
- 12%
- Days to reach leather hard
- 1 days
- Days to dry fully before a bisque
- 10 days
- Days per firing including the cool
- 2 days
- Pieces that dry in one day
- 12 pieces
- Studio hours a week
- 20 h
You get
- Working hours for the batch
- 12.32 h
- Throwing hours
- 5.60 h
- Trimming hours
- 2.99 h
- Finishing and glazing hours
- 3.73 h
- Working hours per piece
- 0.55 h
- Working hours per piece that survives
- 0.62 h
- Days to leather hard for the whole batch
- 1.87 days
- Days to dry fully for the whole batch
- 18.67 days
- Elapsed days from throwing to finished
- 26.53 days
- Lead time in weeks
- 3.79
- Working days the batch takes
- 3.08 days
- Days that are waiting rather than working
- 21.45 days
- Share of the calendar that is work
- 11.6%
- Pieces made per studio hour
- 1.82
- Studio sessions the batch takes
- 4
About 7.7 hours of throwing and trimming, or 11.3 hours with glazing and the failure allowance. Leather hard in about 1.9 days and dry in about 18.7, so the elapsed time from throwing to finished is roughly 25 days for a day and a half of work.
A batch of lidded jars
A slower form: 35 minutes to throw, 15 to trim and 15 to glaze, 12 jars.
You enter
- Pieces in the batch
- 12
- Throwing time per piece
- 35 min
- Trimming time per piece
- 15 min
- Finishing and glazing time per piece
- 15 min
- Failure and seconds allowance
- 20%
- Days to reach leather hard
- 2 days
- Days to dry fully before a bisque
- 14 days
- Days per firing including the cool
- 2 days
- Pieces that dry in one day
- 8 pieces
- Studio hours a week
- 20 h
You get
- Working hours for the batch
- 15.60 h
- Throwing hours
- 8.40 h
- Trimming hours
- 3.60 h
- Finishing and glazing hours
- 3.60 h
- Working hours per piece
- 1.08 h
- Working hours per piece that survives
- 1.30 h
- Days to leather hard for the whole batch
- 3.60 days
- Days to dry fully for the whole batch
- 25.20 days
- Elapsed days from throwing to finished
- 34.80 days
- Lead time in weeks
- 4.97
- Working days the batch takes
- 3.90 days
- Days that are waiting rather than working
- 28.90 days
- Share of the calendar that is work
- 11.2%
- Pieces made per studio hour
- 0.92
- Studio sessions the batch takes
- 4
Thirteen hours of throwing and trimming and 16.6 hours in total, but the calendar is 31 days because a fitted lid needs longer settling and a slower dry. Nearly three weeks of it is waiting.
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Frequently asked questions
How long does it take to throw 20 bowls?
At 15 minutes to throw and 8 to trim, 20 bowls is 460 minutes of wheel and bench work, which is about 7.7 hours, or 9.5 hours once trimming and glazing are included. Add the waits and the calendar is much longer: a day to throw, a day or two to reach leather hard, a trimming session, one to two weeks to dry, then a bisque and a glaze firing with a day each to fire and cool. Three weeks elapsed for 7.7 hours of work is entirely normal.
How long should a piece take to throw?
A simple bowl takes 10 to 20 minutes, a mug with a pulled handle 12 to 25, a lidded jar 25 to 45, and a large or complex form an hour or more. Trimming adds 5 to 10 minutes on a bowl and more where there is a foot ring or a fitted lid, and glazing is another 5 to 15 minutes a piece across a batch. A production thrower repeating one form all day will beat those figures substantially, and a first attempt at a new shape will be much slower.
How long does a pot need to dry before firing?
About 1 to 3 days to reach leather hard, which is when it can be trimmed, and 1 to 2 weeks to be dry enough for a bisque firing. It varies with the thickness of the piece, the humidity and how much air moves around it, so a shelf of thin mugs may be ready in days while a thick sculptural form needs weeks. A piece that still feels cool against your cheek is still holding water, and firing it wet is how a piece explodes in the kiln.
Why does my studio time not match the calendar?
Because most of a pottery timeline is waiting rather than working. This calculator typically shows work at around 15 to 25 percent of the elapsed calendar, with the rest being drying, bisque firing, glazing and the glaze firing with its cool. That is why promising a delivery date from the wheel hours alone is a reliable way to be late. Plan backwards from the delivery date by adding the waits, and treat the firing days as fixed rather than compressible.
How do I allow for failures in a time estimate?
Add the failure percentage to the number of pieces before you calculate the time, because a failed piece consumed the same throwing, trimming and glazing time as one that survived. Ten percent is optimistic on a settled form and twenty is honest on a new one or a new body. The failure also consumes clay, glaze and shelf space, so the pottery cost calculator and this one should be given the same allowance or the two answers will not agree.