The free long exposure calculator for landscape photographers — get the exact shutter speed with any neutral density filter. Stack filters, count stops, shoot with confidence.
The ND number describes the filter's density factor — how many times it multiplies your exposure. Each stop halves the light, so the factor is 2stops. For example, an ND1000 blocks light by a factor of 1,000, which equals 10 stops and transmits only ~0.1% of the light.
| Filter | Stops | Exposure factor | Light transmitted |
|---|
When stacking filters, add the stops and multiply the factors: ND1000 + ND8 = 13 stops (factor 8,192). This calculator handles stacking automatically — just tap every filter in your stack.
1/60 and decimals like 0.5 both work.An ND filter calculator — also called a long exposure calculator — tells you exactly how long your shutter should stay open after you attach a neutral density filter. ND filters are darkened glass that reduce the light reaching your sensor without changing its color, letting you use long exposures in bright daylight. They block light in measured increments called stops: every stop halves the incoming light, so the correct exposure time doubles. Attaching a 10-stop ND1000 means your shutter stays open roughly 1,000× longer.
Doing that math by hand in the field — base shutter times 2 to the power of stops — is slow and error-prone, especially when stacking filters. This free neutral density calculator does it instantly as you type. It supports every common filter from ND2 (1 stop) to ND6400 (13 stops), multi-filter stacking, and custom stop values up to 20. Landscape photographers use it for silky waterfalls with ND8/ND64, smooth seas and streaking clouds with ND1000, and removing people from busy scenes with extreme 12–13 stop exposures.
The calculator runs entirely in your browser — no uploads, no accounts, no waiting. It works offline once loaded, so you can check exposures on location even with no signal. Switch to the “Find Required ND Filter” tab to work backwards: enter the shutter speed your camera meters and the dreamy long exposure you want, and it tells you exactly how many stops you need and which filter (or filter stack) to buy or pack.
new shutter = base shutter × 2stops. For example, 1/60 s with a 10-stop ND1000 becomes 1/60 × 1024 ≈ 17 seconds. This tool applies the formula in real time and supports stacking — stacked filter stops are simply added together.