Film Footage Calculator

Convert film length between feet + frames, metres, total frames and running time for 35 mm, 16 mm, 70 mm, IMAX and 8 mm gauges. Plan reels and platters, and work out what happens when film runs at the wrong speed.

Gauge & Frame Rate

fr/ft
Frame rate
fps
Film speed
—
Metric
—
Per second
—
Frames per foot
—

Length & Running Time

Type into any field and the others update. Changing the gauge or frame rate keeps the value you last typed and recalculates the rest.

ft+fr
m
fr
h:mm:ss:ff, h:mm:ss or mm:ss
This gauge has a non-whole number of frames per foot, so some foot marks fall part-way through a frame. The frames after the + count from the nearest whole frame.
Footage counter
—
Feet (decimal)
—
Metres
—
Total frames
—
Running time (h:mm:ss:ff)
—
Minutes
—

Reels & Platters

Uses the length from the converter above. Reel figures are nominal capacities: a reel holds a little less once leaders and tails are added, so leave some headroom.

ft
ft
Platter capacity depends on the deck diameter and model, so check the manufacturer's figure.
Programme length
—
Run time per full reel
—
Reels needed
—
Changeovers (two projectors)
—
Platter run time
—
On one platter
—

Run time per reel

Speed Mismatch

Film shot at one rate and shown at another runs faster or slower, and its optical or magnetic sound changes pitch by the same ratio. The classic case is 24 fps film shown at 25 fps for PAL television: about 4 % faster and shorter, and about 0.7 of a semitone sharp unless the sound is pitch-corrected.

Presets:
fps
fps
Speed change
—
Running time change
—
New running time
—
Difference
—
Pitch shift
—
In cents
—

Gauge Reference

Gauge Frames / ft ft/min @ 16 ft/min @ 18 ft/min @ 24 m/min @ 24

Quick checks: 35 mm 4-perf at 24 fps runs at 90 ft/min (1,000 ft ≈ 11 min, 2,000 ft ≈ 22 min). 16 mm at 24 fps runs at 36 ft/min. A 50 ft Super 8 cartridge lasts 3 min 20 s at 18 fps.

Notes & References

  • Frames per foot come from the perforation pitch in the SMPTE film dimension standards. 35 mm and 70 mm (KS/BH perforations, 0.1870 in pitch) have 64 perforations per foot, so 4-perf = 16, 3-perf = 21⅓, 2-perf = 32, 70 mm 5-perf = 12.8 and 15-perf = 4.267 frames per foot. 16 mm (0.300 in pitch) = 40, Super 8 (0.1667 in) = 72 and Regular 8 mm (0.150 in) = 80 frames per foot. These are the nominal counts footage counters use.
  • IMAX 15/70 runs horizontally through the projector, so at 24 fps the film moves at about 5.6 ft per second (337.5 ft/min).
  • 1 foot = 0.3048 m exactly. Running time is shown as hours:minutes:seconds:frames at the selected rate.
  • Changeovers assume a two-projector show with one changeover between each reel. Platter shows are normally built up from the shipping reels onto one long roll, so the changeover count doesn't apply.
  • Pitch shift = 12 × log2(projected ÷ shot) semitones. Silent-era films had no single standard speed, so 16 and 18 fps are only typical values.
  • For video frame rates and timecode, see the SMPTE Timecode Calculator.