Time-Lapse Frame Calculator
How to Use This Time-Lapse Frame Calculator
This time-lapse frame calculator helps you quickly work out how many photos you need to capture and how long your final video will be. Enter the total event duration, your capture interval in seconds, and your desired playback frame rate (fps). The calculator then estimates both the total frame count and the finished video length.
To calculate a time-lapse manually:
- Convert the event duration to seconds.
- Divide that duration (in seconds) by the capture interval (in seconds) to get the total number of frames.
- Divide the total frames by your playback fps to get the video length in seconds.
This page explains the formulas behind the calculator, how to interpret the results, and how to choose intervals and frame rates for different types of scenes.
Formulas Behind the Time-Lapse Calculations
The core idea is simple: you capture photos at a fixed interval, then play them back more quickly than real time. Two main quantities matter:
- Total frames to shoot – how many individual photos your camera must take.
- Final video duration – how long the rendered time-lapse clip will last.
We will define the variables as follows:
- D_h = event duration in hours
- D_s = event duration in seconds
- I = capture interval in seconds
- F = playback frame rate in frames per second (fps)
- N = total number of frames (photos)
- T_v = final video duration in seconds
First convert hours to seconds, then compute frames and video length. In MathML form:
Expanded into plain language, the formulas are:
- Event duration in seconds:
D_s = D_h × 3600 - Total frames:
N = D_s ÷ I - Video duration in seconds:
T_v = N ÷ F
The calculator performs these steps instantly, so you can try multiple scenarios to see how interval and fps choices affect the outcome.
Interpreting the Calculator Results
When you enter your event duration, capture interval, and playback fps, the tool returns two key numbers:
- Total number of frames – how many individual photos you will capture over the entire event.
- Final video length – how long the time-lapse clip will last when played back at your chosen frame rate.
Use these results to answer practical planning questions:
- Storage planning – multiply the total frame count by your average file size (for example, 25 MB per RAW or 8 MB per JPEG) to estimate how much card space you will need.
- Battery and power – consider how many shots your camera can take per battery charge and compare that to the required frame count. For long shoots, plan extra batteries or external power.
- Editing expectations – a very short final duration may feel too brief, while an extremely long clip can be tedious. The calculator makes it easy to adjust the interval or fps to hit your target length.
As you tweak the inputs, watch how sensitive the frame count and clip duration are to changes in interval. Halving the interval doubles the number of photos and roughly doubles the editing and storage requirements.
Worked Example: Planning a Sunset Time-Lapse
Suppose you want to capture a two-hour sunset, from the first golden light to full dusk. You decide on the following settings:
- Event duration: 2 hours
- Capture interval: 5 seconds
- Playback frame rate: 30 fps
Step-by-step, the math looks like this.
1. Convert the duration to seconds
Two hours is:
D_s = 2 × 3600 = 7200 seconds
2. Calculate the total number of frames
With a 5-second interval:
N = 7200 ÷ 5 = 1440 frames
You will capture about 1,440 individual photos.
3. Calculate the final video duration
At 30 fps:
T_v = 1440 ÷ 30 = 48 seconds
The finished video will be roughly 48 seconds long. This is long enough to show the evolving colors of the sky, but short enough to stay engaging for most viewers.
4. Storage and power check
If each image file is around 20 MB (for example, shooting RAW on a high-resolution camera), the sequence will require:
1440 × 20 MB ≈ 28,800 MB ≈ 28.8 GB
You should plan for at least a 32 GB card dedicated to this time-lapse, or adjust the interval, image format, or duration to fit your available storage. If your camera manages about 600 shots per battery, 1,440 frames may require three fully charged batteries or an external power source.
Choosing Capture Interval and Frame Rate
Different subjects benefit from different capture intervals. Shorter intervals create smoother motion but generate more photos and longer editing times. Longer intervals compress time more aggressively and can make motion appear choppier.
| Scene type | Typical interval | Suggested playback fps | Result characteristics |
|---|---|---|---|
| Fast traffic or people walking | 0.5 – 2 seconds | 30 – 60 fps | Very smooth motion, fine detail in movement, high frame count. |
| Clouds, cityscapes, crowds | 1 – 10 seconds | 24 – 30 fps | Natural-looking speed, good balance of smoothness and storage use. |
| Sunsets, sunrises, changing light | 3 – 10 seconds | 24 – 30 fps | Gradual color shifts, manageable file counts for long events. |
| Construction projects, plant growth | 20 – 60 seconds | 24 – 30 fps | Strong time compression, jumpier motion is acceptable. |
| Star trails or astrophotography | 20 – 60+ seconds | 24 – 30 fps | Very long events, motion is dominated by the night sky rotation. |
Use these ranges as a starting point. The ideal interval depends on how fast things are changing and how smooth you want the final clip to appear. You can plug different intervals into the calculator to see how your choice affects the frame count and clip length.
For playback frame rate, many creators choose:
- 24 fps for a cinematic look with slightly less storage and processing.
- 30 fps for web and general video platforms.
- 50–60 fps for extra-smooth motion or when you may slow the footage down in post-production.
Planning Storage and Battery Needs
The calculator’s frame count is the foundation for estimating how much storage and power your shoot will require.
1. Estimating storage requirements
- Use the calculator to find the total number of frames.
- Determine your average file size per photo (for example, 10 MB JPEG, 30 MB RAW).
- Multiply frames by file size to get the total storage requirement.
Example: if the calculator shows 2,000 frames and you shoot 12 MB JPEGs:
2,000 × 12 MB = 24,000 MB ≈ 24 GB
You would want at least a 32 GB card, leaving room for overhead and any extra shots.
2. Estimating battery or power needs
- Find your camera’s approximate shots-per-battery rating (from manufacturer specs or experience).
- Divide the required frame count by shots per battery to estimate how many batteries you need.
Example: with 2,000 frames needed and a camera that averages 700 shots per battery:
2,000 ÷ 700 ≈ 2.9
You should plan on three fully charged batteries or an external power source to be safe. A small buffer helps cover intervalometer tests, misfires, and any extra frames at the beginning or end of the event.
Assumptions and Limitations
The time-lapse frame calculator is designed as a planning tool. For simplicity, it makes several assumptions that you should keep in mind when using the results:
- Constant capture interval – it assumes the camera triggers perfectly on schedule at every interval, with no missed shots.
- No interruptions – it does not account for breaks to change batteries, swap memory cards, or adjust composition.
- No dropped frames – storage write delays, buffer limitations, or errors that cause skipped images are not included.
- Stable exposure settings – changes in shutter speed, aperture, or ISO do not affect the timing in the calculation, even though they may influence your real shooting cadence.
- Fixed frame rate in playback – the tool assumes you play back at a constant fps. Variable frame rate edits or speed ramps in your editor will change the final duration.
Because of these assumptions, think of the outputs as idealized values. In real-world shooting, it is wise to add extra time, storage, and power margins to cover unexpected delays or camera behavior.
Frequently Asked Questions
What is a good interval for a sunset time-lapse?
For sunsets and similar changing-light scenes, an interval between 3 and 10 seconds often works well. Use the calculator to test a few values and check how they affect the total frame count and your desired final clip duration.
How can I find out how long my time-lapse video will be?
Enter your event duration, capture interval, and playback fps into the calculator. It will show the total frames and the final video length in seconds so you can adjust the interval or frame rate to hit your target duration.
What frame rate should I use for time-lapse?
Most time-lapse clips are played back at 24 or 30 fps. If you want extra-smooth motion or plan to slow the footage down in editing, you can choose higher frame rates like 50 or 60 fps and see how that affects the final clip length in the calculator.
Can I use variable intervals with this calculator?
This tool assumes a single, constant interval for the entire shoot. If you plan to change intervals during the event, treat each segment separately, calculate its frames and duration, and then add the results together.