Embroidery run time: how to estimate it from stitch count, speed, colour changes and hooping

Stitch count divided by speed is where every estimate starts and where most of them stop, which is why quotes come out optimistic. The rest of the time is in things the file does not count. This guide puts numbers on each, so the calculator gives a time you can plan around.

Rated speed versus real speed

Machines are sold on their maximum stitches per minute: 850 for a Brother PE800, 1,000 for a Brother PR series or a Ricoma, 1,200 for a Tajima. Nobody runs a whole design at that. The machine slows automatically for stitches longer than about 7 mm, for jumps, and on many models for dense satin; operators run at 80 to 90 % to reduce thread breaks on knits and caps; and the first and last stitches of every run are at a crawl.

Realistic averages for planning:

| Machine | Rated | Plan on | |---|---|---| | Home single-needle (Brother PE, Janome MC, Bernina 5/7) | 650–1,000 | 550–700 | | Home multi-needle (Brother PR, Janome MB, Baby Lock Array) | 1,000 | 750–850 | | Commercial single-head (Ricoma, Melco, Tajima, Barudan) | 1,000–1,500 | 800–1,000 | | Commercial multi-head, per head | 1,000–1,200 | 800–900 |

Time your own machine once on a design you know, and use that. It is the single biggest correction to any estimate.

The parts that are not stitches

Colour changes. On a single-needle machine, each is a stop, a thread change, a trim, a re-thread and a restart: 30 seconds for a practised operator, a minute if the machine is across the room. Multi-needle machines switch needles in a couple of seconds but still trim and restart. A design's change count is in the viewer and the pre-flight report.

Trims. Two to five seconds each with an automatic trimmer; the machine stops, cuts, moves, and restarts slowly. A design with 80 trims spends three to five minutes trimming. Without a trimmer, trims are manual cuts after the run.

Jumps. The frame moves without stitching, slowly. A design with long jumps between separate elements spends more time travelling than the stitch count suggests. Jumps and trims explains which ones to remove.

Hooping. 30 to 45 seconds for a t-shirt, a minute for a jacket, two for a cap on a cap frame. It is per piece and it does not go away on a multi-head, where each head has to be hooped.

Everything else. Thread breaks (two minutes each), bobbin changes (a bobbin lasts 30,000 to 40,000 stitches), checking the first piece, trimming jump threads by hand. Plan 10 to 15 % on top for these on a good day.

The formula the calculator uses

minutes per piece = stitches ÷ speed
                  + colour changes × 0.5
                  + trims × 0.05
                  + hooping (0.75)
hours for the run = minutes per piece × quantity ÷ heads ÷ 60

At 650 spm, a 7,800-stitch three-colour logo with 20 trims: 12 + 1.5 + 1 + 0.75 = 15.3 minutes per piece. Twenty-four pieces on one head: 6.1 hours. On a four-head, 1.5 hours of machine time but four hoopings per cycle, so operator time is the same.

What shortens a run

• Fewer colour changes. Merge same-colour blocks that follow each other (cleanup does it); ask the digitiser to sequence colours to sew all of one colour before moving on where the design allows.
• Fewer trims. Designs that trim at every object are usually auto-digitised. A digitiser can travel under later stitches instead.
• Speed where it is safe. Run faster on twill and caps, slower on knits and metallic thread. The break you avoid saves more than the speed you gain.
• Batching names. Set the lettering once, generate every name, hoop in sequence. Batch names.

Timing your machine

1. Pick a design of 5,000 to 10,000 stitches you sew often. Note its stitch count, colour changes and trims from the viewer.
2. Time three pieces from pressing start to the end stitch, on your usual fabric, without touching the speed control.
3. Subtract the changes (count × your measured change time) from the total. Divide stitches by the remaining minutes. That is your effective speed.
4. Put it in the calculator as the machine speed. Re-time once a year or after a service.

The number you get is usually 15 to 30 % under the rated speed. Estimates made with it will be right to within a few minutes on a run, which is what a quote needs.