diff --git a/crates/nu-cli/src/cli.rs b/crates/nu-cli/src/cli.rs
index f18c2caefa..e3c5d2d478 100644
--- a/crates/nu-cli/src/cli.rs
+++ b/crates/nu-cli/src/cli.rs
@@ -180,6 +180,7 @@ pub fn create_default_context(interactive: bool) -> Result<EvaluationContext, Bo
             whole_stream_command(Nth),
             whole_stream_command(Drop),
             whole_stream_command(Format),
+            whole_stream_command(FileSize),
             whole_stream_command(Where),
             whole_stream_command(If),
             whole_stream_command(Compact),
diff --git a/crates/nu-cli/src/commands.rs b/crates/nu-cli/src/commands.rs
index 93be91f6e4..07dc63e389 100644
--- a/crates/nu-cli/src/commands.rs
+++ b/crates/nu-cli/src/commands.rs
@@ -177,7 +177,7 @@ pub(crate) use exec::Exec;
 pub(crate) use exit::Exit;
 pub(crate) use first::First;
 pub(crate) use flatten::Command as Flatten;
-pub(crate) use format::Format;
+pub(crate) use format::{FileSize, Format};
 pub(crate) use from::From;
 pub(crate) use from_csv::FromCSV;
 pub(crate) use from_eml::FromEML;
diff --git a/crates/nu-cli/src/commands/format.rs b/crates/nu-cli/src/commands/format/command.rs
similarity index 100%
rename from crates/nu-cli/src/commands/format.rs
rename to crates/nu-cli/src/commands/format/command.rs
diff --git a/crates/nu-cli/src/commands/format/format_filesize.rs b/crates/nu-cli/src/commands/format/format_filesize.rs
new file mode 100644
index 0000000000..591d2a0573
--- /dev/null
+++ b/crates/nu-cli/src/commands/format/format_filesize.rs
@@ -0,0 +1,194 @@
+use crate::prelude::*;
+use nu_errors::ShellError;
+
+use crate::commands::WholeStreamCommand;
+use nu_protocol::{
+    ColumnPath, Primitive::Filesize, ReturnSuccess, Signature, SyntaxShape, UntaggedValue,
+    UntaggedValue::Primitive, Value,
+};
+use nu_source::Tagged;
+use nu_value_ext::get_data_by_column_path;
+
+use num_format::{Locale, ToFormattedString};
+
+pub struct FileSize;
+
+#[derive(Deserialize)]
+pub struct Arguments {
+    field: ColumnPath,
+    format: Tagged<String>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for FileSize {
+    fn name(&self) -> &str {
+        "format filesize"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("format filesize")
+            .required(
+                "field",
+                SyntaxShape::ColumnPath,
+                "the name of the column to update",
+            )
+            .required(
+                "format value",
+                SyntaxShape::String,
+                "the format into which convert the filesizes",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Converts a column of filesizes to some specified format"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        filesize(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Convert the size row to KB",
+                example: "ls | format filesize size KB",
+                result: None,
+            },
+            Example {
+                description: "Convert the apparent row to B",
+                example: "du | format filesize apparent B",
+                result: None,
+            },
+        ]
+    }
+}
+
+async fn process_row(
+    input: Value,
+    format: Tagged<String>,
+    field: Arc<ColumnPath>,
+) -> Result<OutputStream, ShellError> {
+    Ok({
+        let replace_for = get_data_by_column_path(&input, &field, move |_, _, error| error);
+        match replace_for {
+            Ok(s) => match convert_bytes_to_string_using_format(s, format) {
+                Ok(b) => OutputStream::one(ReturnSuccess::value(
+                    input.replace_data_at_column_path(&field, b).expect("Given that the existance check was already done, this souldn't trigger never"),
+                )),
+                Err(e) => OutputStream::one(Err(e)),
+            },
+            Err(e) => OutputStream::one(Err(e)),
+        }
+    })
+}
+
+async fn filesize(
+    raw_args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = registry.clone();
+    let (Arguments { field, format }, input) = raw_args.process(&registry).await?;
+    let field = Arc::new(field);
+
+    Ok(input
+        .then(move |input| {
+            let format = format.clone();
+            let field = field.clone();
+
+            async {
+                match process_row(input, format, field).await {
+                    Ok(s) => s,
+                    Err(e) => OutputStream::one(Err(e)),
+                }
+            }
+        })
+        .flatten()
+        .to_output_stream())
+}
+
+fn convert_bytes_to_string_using_format(
+    bytes: Value,
+    format: Tagged<String>,
+) -> Result<Value, ShellError> {
+    match bytes.value {
+        Primitive(Filesize(b)) => {
+            let byte = byte_unit::Byte::from_bytes(b as u128);
+            let value = match format.item().to_lowercase().as_str() {
+                "b" => Ok(UntaggedValue::string(b.to_formatted_string(&Locale::en))),
+                "kb" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::KB).to_string(),
+                )),
+                "kib" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::KiB).to_string(),
+                )),
+                "mb" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::MB).to_string(),
+                )),
+                "mib" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::MiB).to_string(),
+                )),
+                "gb" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::GB).to_string(),
+                )),
+                "gib" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::GiB).to_string(),
+                )),
+                "tb" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::TB).to_string(),
+                )),
+                "tib" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::TiB).to_string(),
+                )),
+                "pb" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::PB).to_string(),
+                )),
+                "pib" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::PiB).to_string(),
+                )),
+                "eb" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::EB).to_string(),
+                )),
+                "eib" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::EiB).to_string(),
+                )),
+                "zb" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::ZB).to_string(),
+                )),
+                "zib" => Ok(UntaggedValue::string(
+                    byte.get_adjusted_unit(byte_unit::ByteUnit::ZiB).to_string(),
+                )),
+                _ => Err(ShellError::labeled_error(
+                    format!("Invalid format code: {:}", format.item()),
+                    "invalid format",
+                    format.tag(),
+                )),
+            };
+            match value {
+                Ok(b) => Ok(Value { value: b, ..bytes }),
+                Err(e) => Err(e),
+            }
+        }
+        _ => Err(ShellError::labeled_error(
+            "the data in this row is not of the type filesize",
+            "invalid row type",
+            bytes.tag(),
+        )),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::FileSize;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test as test_examples;
+
+        Ok(test_examples(FileSize {})?)
+    }
+}
diff --git a/crates/nu-cli/src/commands/format/mod.rs b/crates/nu-cli/src/commands/format/mod.rs
new file mode 100644
index 0000000000..cd8267069c
--- /dev/null
+++ b/crates/nu-cli/src/commands/format/mod.rs
@@ -0,0 +1,5 @@
+pub mod command;
+pub mod format_filesize;
+
+pub use command::Format;
+pub use format_filesize::FileSize;
diff --git a/crates/nu-cli/tests/commands/format.rs b/crates/nu-cli/tests/commands/format.rs
index d827781fd8..eee38afce2 100644
--- a/crates/nu-cli/tests/commands/format.rs
+++ b/crates/nu-cli/tests/commands/format.rs
@@ -1,3 +1,5 @@
+use nu_test_support::fs::Stub::EmptyFile;
+use nu_test_support::playground::Playground;
 use nu_test_support::{nu, pipeline};
 
 #[test]
@@ -42,3 +44,26 @@ fn can_use_variables() {
 
     assert_eq!(actual.out, "nu is a new type of shell");
 }
+
+#[test]
+fn format_filesize_works() {
+    Playground::setup("format_filesize_test_1", |dirs, sandbox| {
+        sandbox.with_files(vec![
+            EmptyFile("yehuda.txt"),
+            EmptyFile("jonathan.txt"),
+            EmptyFile("andres.txt"),
+        ]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                ls
+                | format filesize size KB
+                | get size
+                | first
+            "#
+        ));
+
+        assert_eq!(actual.out, "0.01 KB");
+    })
+}