Provided by: gdal-bin_3.12.0+dfsg-1_amd64 
NAME
gdal_calc - Command line raster calculator with numpy syntax.
SYNOPSIS
gdal_calc [--help] [--help-general]
--calc=expression --outfile=<out_filename> [-A <filename>]
[--A_band=<n>] [-B...-Z <filename>] [<other_options>]
DESCRIPTION
Command line raster calculator with numpy syntax. Use any basic arithmetic supported by numpy arrays such
as +, -, *, and / along with logical operators such as >. Note that all files must have the same
dimensions (unless the --extent option is used), but no projection checking is performed (unless the
--projectionCheck option is used).
NOTE:
gdal_calc is a Python utility, and is only available if GDAL Python bindings are available.
--help Show this help message and exit
--help-general
Gives a brief usage message for the generic GDAL commandline options and exit.
--calc=<expression>
Calculation in numpy syntax using +, -, /, *, or any numpy array functions (i.e. log10()).
Multiple --calc options can be listed to produce a multiband file (GDAL >= 3.2). See Example 10.
-A <filename>
Input GDAL raster file, you can use any letter (a-z, A-Z). (lower case supported since GDAL 3.3)
A letter may be repeated, or several values (separated by space) can be provided (GDAL >= 3.3).
The effect will be to create a 3D numpy array. Since GDAL 3.5, wildcard exceptions (using ?, *)
are supported for all shells/platforms. In such a case, the calculation formula must use this
input as a 3D array and must return a 2D array (see Example 3). If the calculation does not
return a 2D array an error will be generated.
--A_band=<n>
Number of raster band for file A (default 1).
--outfile=<filename>
Output file to generate or fill.
--NoDataValue=<value>
Output NoDataValue (default datatype specific value). To indicate not setting a NoDataValue use
--NoDataValue=none (GDAL >= 3.3)
NOTE:
Using the Python API: None value will indicate default datatype specific value. 'none' value
will indicate not setting a NoDataValue.
--hideNoData
Added in version 3.3.
Ignores the input bands NoDataValue. By default, the input bands NoDataValue are not
participating in the calculation. By setting this setting - no special treatment will be
performed on the input NoDataValue. and they will be participating in the calculation as any other
value. The output will not have a set NoDataValue, unless you explicitly specified a specific
value by setting --NoDataValue=<value>.
--type=<datatype>
Output datatype, must be one of [Byte, Int8, UInt16, Int16, UInt32, Int32, UInt64, Int64, Float64,
Float32, CInt16, CInt32, CFloat64, CFloat32].
NOTE:
Despite the datatype set using --type, when doing intermediate arithmetic operations using
operands of the same type, the operation result will honor the original datatype. This may lead
into unexpected results in the final result.
NOTE:
UInt64, Int64, CInt16, CInt32, CFloat32, CFloat64 have been added in GDAL 3.5.3 Int8 has been
added in GDAL 3.7
--format=<gdal_format>
GDAL format for output file.
--color-table=<filename>
Allows specifying a filename of a color table (or a ColorTable object) (with Palette Index
interpretation) to be used for the output raster. Supported formats: txt (i.e. like gdaldem, but
color names are not supported), qlr, qml (i.e. exported from QGIS)
--extent=<option>
Added in version 3.3.
This option determines how to handle rasters with different extents. This option is mutually
exclusive with the projwin option, which is used for providing a custom extent.
For all the options below the pixel size (resolution) and SRS (Spatial Reference System) of all
the input rasters must be the same.
ignore (default) - only the dimensions of the rasters are compared. if the dimensions do not agree
the operation will fail.
fail - the dimensions and the extent (bounds) of the rasters must agree, otherwise the operation
will fail.
union - the extent (bounds) of the output will be the minimal rectangle that contains all the
input extents.
intersect - the extent (bounds) of the output will be the maximal rectangle that is contained in
all the input extents.
--projwin <ulx> <uly> <lrx> <lry>
Added in version 3.3.
This option provides a custom extent for the output, it is mutually exclusive with the extent
option.
--projectionCheck
Added in version 3.3.
By default, no projection checking will be performed. By setting this option, if the projection
is not the same for all bands then the operation will fail.
--creation-option=<option>
Passes a creation option to the output format driver. Multiple options may be listed. See format
specific documentation for legal creation options for each format.
--co=<option>
The same as creation-option.
--allBands=[a-z, A-Z]
Apply the expression to all bands of a given raster. When --allBands is used, --calc may be
specified only once. See Example 11 and Example 12.
--overwrite
Overwrite output file if it already exists. Overwriting must be understood here as deleting and
recreating the file from scratch. Note that if this option is not specified and the output file
already exists, it will be updated in place.
--debug
Print debugging information.
--quiet
Suppress progress messages.
PYTHON OPTIONS
Added in version 3.3.
The following options are available by using the Python interface of gdal_calc. They are not available
using the command prompt.
user_namespace
A dictionary of custom functions or other names to be available for use in the Calc expression.
return_ds
If enabled, the output dataset will be returned from the function and not closed.
color_table
Allows specifying a ColorTable object (with Palette Index interpretation) to be used for the
output raster.
EXAMPLES
Example 1: Average of two files
gdal_calc -A input1.tif -B input2.tif --outfile=result.tif --calc="(A+B)/2"
CAUTION:
If A and B inputs both have integer data types, integer division will be performed. To avoid this,
you can convert of one of the operands to a floating point type before the division operation.
gdal_calc -A input.tif -B input2.tif --outfile=result.tif --calc="(A.astype(numpy.float64) + B) / 2"
Example 2: Summing three files
gdal_calc -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="A+B+C"
Example 3: Combining three files into a 3D array and summing
gdal_calc -A input1.tif -A input2.tif -A input3.tif --outfile=result.tif --calc="numpy.sum(A,axis=0)".
Example 4: Average of three files
gdal_calc -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="(A+B+C)/3"
Example 5: Average of three files, using 3D array
gdal_calc -A input1.tif input2.tif input3.tif --outfile=result.tif --calc="numpy.average(a,axis=0)".
Example 6: Maximum of three files
gdal_calc -A input1.tif -B input2.tif -C input3.tif --outfile=result.tif --calc="numpy.max((A,B,C),axis=0)"
Example 7: Maximum of three files, using a 3D array
gdal_calc -A input1.tif input2.tif input3.tif --outfile=result.tif --calc="numpy.max(A,axis=0)"
Example 8: Setting values of zero and below to NODATA
gdal_calc -A input.tif --outfile=result.tif --calc="A*(A>0)" --NoDataValue=0
Example 9: Using logical operator to keep a range of values from input
gdal_calc -A input.tif --outfile=result.tif --calc="A*logical_and(A>100,A<150)"
Example 10: Performing two calculations and storing results in separate bands
gdal_calc -A input.tif --A_band=1 -B input.tif --B_band=2 \
--outfile=result.tif --calc="(A+B)/2" --calc="B*logical_and(A>100,A<150)"
Example 11: Add a raster to each band in a 3-band raster
gdal_calc -A 3band.tif -B 1band.tif --outfile result.tif --calc "A+B" --allBands A
The result will have three bands, where each band contains the values of 1band.tif added to the
corresponding band in 3band.tif.
Example 12: Add two three-band rasters
gdal_calc -A 3band_a.tif -B 3band_b.tif --outfile result.tif --calc "A+B" --allBands A --allBands B
The result will have three bands, where each band contains the values of the corresponding band of
3band_a.tif added to the corresponding band of 3band_b.tif.
AUTHOR
Chris Yesson <chris dot yesson at ioz dot ac dot uk>, Etienne Tourigny <etourigny dot dev at gmail dot
com>
COPYRIGHT
1998-2025
Nov 07, 2025 GDAL_CALC(1)