diff --git a/arduino/builder/sizer.go b/arduino/builder/sizer.go
deleted file mode 100644
index 911f261af67..00000000000
--- a/arduino/builder/sizer.go
+++ /dev/null
@@ -1,26 +0,0 @@
-package builder
-
-import rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
-
-// ExecutableSectionSize represents a section of the executable output file
-type ExecutableSectionSize struct {
-	Name    string `json:"name"`
-	Size    int    `json:"size"`
-	MaxSize int    `json:"max_size"`
-}
-
-// ExecutablesFileSections is an array of ExecutablesFileSection
-type ExecutablesFileSections []ExecutableSectionSize
-
-// ToRPCExecutableSectionSizeArray transforms this array into a []*rpc.ExecutableSectionSize
-func (s ExecutablesFileSections) ToRPCExecutableSectionSizeArray() []*rpc.ExecutableSectionSize {
-	res := []*rpc.ExecutableSectionSize{}
-	for _, section := range s {
-		res = append(res, &rpc.ExecutableSectionSize{
-			Name:    section.Name,
-			Size:    int64(section.Size),
-			MaxSize: int64(section.MaxSize),
-		})
-	}
-	return res
-}
diff --git a/legacy/builder/phases/sizer.go b/arduino/builder/sizer/sizer.go
similarity index 87%
rename from legacy/builder/phases/sizer.go
rename to arduino/builder/sizer/sizer.go
index bb96a7aaeb2..195ca3c1413 100644
--- a/legacy/builder/phases/sizer.go
+++ b/arduino/builder/sizer/sizer.go
@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to license@arduino.cc.
 
-package phases
+package sizer
 
 import (
 	"encoding/json"
@@ -22,22 +22,46 @@ import (
 	"regexp"
 	"strconv"
 
-	"github.com/arduino/arduino-cli/arduino/builder"
 	"github.com/arduino/arduino-cli/arduino/builder/utils"
 	"github.com/arduino/arduino-cli/i18n"
+	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
 	"github.com/arduino/go-properties-orderedmap"
 	"github.com/pkg/errors"
 )
 
 var tr = i18n.Tr
 
-func Sizer(
+// ExecutableSectionSize represents a section of the executable output file
+type ExecutableSectionSize struct {
+	Name    string `json:"name"`
+	Size    int    `json:"size"`
+	MaxSize int    `json:"max_size"`
+}
+
+// ExecutablesFileSections is an array of ExecutablesFileSection
+type ExecutablesFileSections []ExecutableSectionSize
+
+// ToRPCExecutableSectionSizeArray transforms this array into a []*rpc.ExecutableSectionSize
+func (s ExecutablesFileSections) ToRPCExecutableSectionSizeArray() []*rpc.ExecutableSectionSize {
+	res := []*rpc.ExecutableSectionSize{}
+	for _, section := range s {
+		res = append(res, &rpc.ExecutableSectionSize{
+			Name:    section.Name,
+			Size:    int64(section.Size),
+			MaxSize: int64(section.MaxSize),
+		})
+	}
+	return res
+}
+
+// Size fixdoc
+func Size(
 	onlyUpdateCompilationDatabase, sketchError, verbose bool,
 	buildProperties *properties.Map,
 	stdoutWriter, stderrWriter io.Writer,
 	printInfoFn, printWarnFn func(msg string),
 	warningsLevel string,
-) (builder.ExecutablesFileSections, error) {
+) (ExecutablesFileSections, error) {
 	if onlyUpdateCompilationDatabase || sketchError {
 		return nil, nil
 	}
@@ -53,7 +77,7 @@ func checkSizeAdvanced(buildProperties *properties.Map,
 	verbose bool,
 	stdoutWriter, stderrWriter io.Writer,
 	printInfoFn, printWarnFn func(msg string),
-) (builder.ExecutablesFileSections, error) {
+) (ExecutablesFileSections, error) {
 	command, err := utils.PrepareCommandForRecipe(buildProperties, "recipe.advanced_size.pattern", false)
 	if err != nil {
 		return nil, errors.New(tr("Error while determining sketch size: %s", err))
@@ -74,7 +98,7 @@ func checkSizeAdvanced(buildProperties *properties.Map,
 		// likely be printed in red. Errors will stop build/upload.
 		Severity string `json:"severity"`
 		// Sections are the sections sizes for machine readable use
-		Sections []builder.ExecutableSectionSize `json:"sections"`
+		Sections []ExecutableSectionSize `json:"sections"`
 		// ErrorMessage is a one line error message like:
 		// "text section exceeds available space in board"
 		// it must be set when Severity is "error"
@@ -106,7 +130,7 @@ func checkSize(buildProperties *properties.Map,
 	stdoutWriter, stderrWriter io.Writer,
 	printInfoFn, printWarnFn func(msg string),
 	warningsLevel string,
-) (builder.ExecutablesFileSections, error) {
+) (ExecutablesFileSections, error) {
 	properties := buildProperties.Clone()
 	properties.Set("compiler.warning_flags", properties.Get("compiler.warning_flags."+warningsLevel))
 
@@ -152,7 +176,7 @@ func checkSize(buildProperties *properties.Map,
 		}
 	}
 
-	executableSectionsSize := []builder.ExecutableSectionSize{
+	executableSectionsSize := []ExecutableSectionSize{
 		{
 			Name:    "text",
 			Size:    textSize,
@@ -160,7 +184,7 @@ func checkSize(buildProperties *properties.Map,
 		},
 	}
 	if maxDataSize > 0 {
-		executableSectionsSize = append(executableSectionsSize, builder.ExecutableSectionSize{
+		executableSectionsSize = append(executableSectionsSize, ExecutableSectionSize{
 			Name:    "data",
 			Size:    dataSize,
 			MaxSize: maxDataSize,
diff --git a/legacy/builder/phases/sizer_test.go b/arduino/builder/sizer/sizer_test.go
similarity index 99%
rename from legacy/builder/phases/sizer_test.go
rename to arduino/builder/sizer/sizer_test.go
index 42e26fdcfa3..42c3b323d42 100644
--- a/legacy/builder/phases/sizer_test.go
+++ b/arduino/builder/sizer/sizer_test.go
@@ -13,7 +13,7 @@
 // Arduino software without disclosing the source code of your own applications.
 // To purchase a commercial license, send an email to license@arduino.cc.
 
-package phases
+package sizer
 
 import (
 	"testing"
diff --git a/legacy/builder/builder.go b/legacy/builder/builder.go
index 135644e29bc..a0657046922 100644
--- a/legacy/builder/builder.go
+++ b/legacy/builder/builder.go
@@ -21,9 +21,9 @@ import (
 
 	"github.com/arduino/arduino-cli/arduino/builder"
 	"github.com/arduino/arduino-cli/arduino/builder/preprocessor"
+	"github.com/arduino/arduino-cli/arduino/builder/sizer"
 	"github.com/arduino/arduino-cli/arduino/sketch"
 	"github.com/arduino/arduino-cli/i18n"
-	"github.com/arduino/arduino-cli/legacy/builder/phases"
 	"github.com/arduino/arduino-cli/legacy/builder/types"
 	"github.com/arduino/go-paths-helper"
 	properties "github.com/arduino/go-properties-orderedmap"
@@ -273,7 +273,7 @@ func (s *Builder) Run(ctx *types.Context) error {
 		}),
 
 		types.BareCommand(func(ctx *types.Context) error {
-			executableSectionsSize, err := phases.Sizer(
+			executableSectionsSize, err := sizer.Size(
 				ctx.OnlyUpdateCompilationDatabase, mainErr != nil, ctx.Verbose,
 				ctx.BuildProperties,
 				ctx.Stdout, ctx.Stderr,
diff --git a/legacy/builder/types/context.go b/legacy/builder/types/context.go
index 4b6383ad9f8..7c5f394fa24 100644
--- a/legacy/builder/types/context.go
+++ b/legacy/builder/types/context.go
@@ -25,6 +25,7 @@ import (
 	"github.com/arduino/arduino-cli/arduino/builder/compilation"
 	"github.com/arduino/arduino-cli/arduino/builder/detector"
 	"github.com/arduino/arduino-cli/arduino/builder/progress"
+	"github.com/arduino/arduino-cli/arduino/builder/sizer"
 	"github.com/arduino/arduino-cli/arduino/cores"
 	"github.com/arduino/arduino-cli/arduino/cores/packagemanager"
 	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
@@ -88,7 +89,7 @@ type Context struct {
 	stdLock sync.Mutex
 
 	// Sizer results
-	ExecutableSectionsSize builder.ExecutablesFileSections
+	ExecutableSectionsSize sizer.ExecutablesFileSections
 
 	// Compilation Database to build/update
 	CompilationDatabase *compilation.Database