Estimate TIFF compression savings for LZW, ZIP, or none

It reports the estimated output size alongside the likely savings in megabytes and percent. The calculation is deterministic and immediate, so it is useful when you need a storage or transfer estimate before encoding a batch. Because TIFF compression depends strongly on pixel content, the result is presented as a typical range rather than a guaranteed final size.

Start with the true uncompressed TIFF size

Enter the size the TIFF would occupy without compression, expressed in megabytes. This is the correct baseline because it represents the pixel data and TIFF structure before LZW or ZIP reduces repeated information. If you only have an already compressed file, its current size is not a reliable substitute: applying a second ratio to that value would usually understate the expected output. For a planned image, derive the baseline from pixel width, pixel height, samples per pixel, bits per sample, and the number of pages, then allow for TIFF metadata and layout overhead. For an existing workflow, the uncompressed size reported by an imaging application or encoder is usually the easiest input. The calculator accepts positive finite decimal values, so both small scans and large archival batches can be modeled. Keep the same definition of megabyte across your planning sheet and this estimate. The result is intended for capacity planning, upload forecasting, and comparison between methods, not as a byte-exact prediction of a particular encoder run.

Understand the LZW, ZIP, and none ranges

Choose the method your TIFF writer will use. LZW is modeled as producing roughly 45% to 75% of the uncompressed size, while ZIP is modeled as producing roughly 30% to 60%. Both are lossless methods, so these ranges describe storage reduction rather than a change in image quality. Selecting none returns exactly 100% of the supplied baseline and zero savings, which is useful as a control when comparing storage plans. The output gives a minimum and maximum estimated file size. It also reverses that interval into a conservative-to-optimistic savings range in both megabytes and percent. A lower output-size estimate corresponds to greater savings, while a higher output-size estimate corresponds to smaller savings. These fixed planning ratios make repeated calls reproducible and easy to audit. They do not inspect image pixels or imitate a particular TIFF library. The model therefore answers a budgeting question consistently while remaining honest about the variability of real lossless compression.

Use the estimate with the right safety margin

Treat the returned interval as a typical planning band, not a hard limit. Photographs, noisy scans, already optimized imagery, unusual bit depths, tiled layouts, multiple pages, embedded previews, color profiles, and extensive metadata can all move the final file outside the estimated range. Flat graphics, masks, diagrams, and documents with large repeated regions often compress more effectively than detailed photographic material. Encoder settings and predictor choices can also change the result even when the method name is the same. For storage procurement, use the upper end of the estimated-size range and add an operational margin for metadata, filesystem allocation, revisions, and growth. For bandwidth planning, multiply that conservative figure by the expected number of files and account for retries or replicated transfers. If exact sizing matters, encode a representative sample with the same software and settings that production will use, measure the observed ratios, and use those measurements for the final forecast. This calculator remains useful as an early, consistent comparison before such a sample exists.