diff --git a/.gitmodules b/.gitmodules
index 7828c19a..a0fe596c 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -31,3 +31,6 @@
 [submodule "external/date"]
 	path = external/date
 	url = https://github.com/HowardHinnant/date.git
+[submodule "external/units"]
+	path = external/units
+	url = https://github.com/nholthaus/units.git
diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index 65b2ef20..806b603b 100644
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -10,7 +10,8 @@ set_property(DIRECTORY
              hsluv-c.cmake
              imgui.cmake
              mapbox-gl-native.cmake
-             stb.cmake)
+             stb.cmake
+             units.cmake)
 
 include(aws-sdk-cpp.cmake)
 include(date.cmake)
@@ -19,3 +20,4 @@ include(hsluv-c.cmake)
 include(imgui.cmake)
 include(mapbox-gl-native.cmake)
 include(stb.cmake)
+include(units.cmake)
diff --git a/external/units b/external/units
new file mode 160000
index 00000000..da6dd917
--- /dev/null
+++ b/external/units
@@ -0,0 +1 @@
+Subproject commit da6dd9176e8515323c75030d5e51ee19cf6c9afd
diff --git a/external/units.cmake b/external/units.cmake
new file mode 100644
index 00000000..d037ae54
--- /dev/null
+++ b/external/units.cmake
@@ -0,0 +1,4 @@
+cmake_minimum_required(VERSION 3.20)
+set(PROJECT_NAME scwx-units)
+
+add_subdirectory(units)
diff --git a/scwx-qt/source/scwx/qt/gl/draw/placefile_icons.cpp b/scwx-qt/source/scwx/qt/gl/draw/placefile_icons.cpp
index dbbc2308..5b8c876c 100644
--- a/scwx-qt/source/scwx/qt/gl/draw/placefile_icons.cpp
+++ b/scwx-qt/source/scwx/qt/gl/draw/placefile_icons.cpp
@@ -232,11 +232,9 @@ void PlacefileIcons::Render(
       if (p->thresholded_)
       {
          // If thresholding is enabled, set the map distance
-         // TODO: nautical miles
-         auto mapDistance =
-            util::maplibre::GetMapDistance(params).value() / 1852.0f;
-         gl.glUniform1f(p->uMapDistanceLocation_,
-                        static_cast<float>(mapDistance));
+         units::length::nautical_miles<float> mapDistance =
+            util::maplibre::GetMapDistance(params);
+         gl.glUniform1f(p->uMapDistanceLocation_, mapDistance.value());
       }
       else
       {
@@ -328,9 +326,10 @@ void PlacefileIcons::Impl::Update()
             continue;
          }
 
-         // TODO: nautical miles
-         GLint threshold =
-            static_cast<GLint>(std::roundf(di->threshold_.value() / 1852.0f));
+         // Threshold value
+         units::length::nautical_miles<double> threshold = di->threshold_;
+         GLint                                 thresholdValue =
+            static_cast<GLint>(std::round(threshold.value()));
 
          // Latitude and longitude coordinates in degrees
          const float lat = static_cast<float>(di->latitude_);
@@ -355,8 +354,8 @@ void PlacefileIcons::Impl::Update()
          const float by = std::roundf(ty - ih);
 
          // Angle in degrees
-         // TODO: Properly convert
-         const float a = static_cast<float>(di->angle_.value());
+         units::angle::degrees<float> angle = di->angle_;
+         const float                  a     = angle.value();
 
          // Texture coordinates
          const std::size_t iconRow    = (di->iconNumber_ - 1) / icon.columns_;
@@ -387,12 +386,12 @@ void PlacefileIcons::Impl::Update()
                           lat, lon, lx, ty, ls, tt, mc0, mc1, mc2, mc3, a  // TL
                        });
          thresholds.insert(thresholds.end(),
-                           {threshold, //
-                            threshold,
-                            threshold,
-                            threshold,
-                            threshold,
-                            threshold});
+                           {thresholdValue, //
+                            thresholdValue,
+                            thresholdValue,
+                            thresholdValue,
+                            thresholdValue,
+                            thresholdValue});
 
          numVertices_ += 6;
       }
diff --git a/scwx-qt/source/scwx/qt/gl/draw/placefile_polygons.cpp b/scwx-qt/source/scwx/qt/gl/draw/placefile_polygons.cpp
index 202a5c0e..7bb54027 100644
--- a/scwx-qt/source/scwx/qt/gl/draw/placefile_polygons.cpp
+++ b/scwx-qt/source/scwx/qt/gl/draw/placefile_polygons.cpp
@@ -6,7 +6,6 @@
 
 #include <GL/glu.h>
 #include <boost/container/stable_vector.hpp>
-#include <boost/units/base_units/metric/nautical_mile.hpp>
 
 #if defined(_WIN32)
 typedef void (*_GLUfuncptr)(void);
@@ -216,11 +215,9 @@ void PlacefilePolygons::Render(
       if (p->thresholded_)
       {
          // If thresholding is enabled, set the map distance
-         // TODO: nautical miles
-         auto mapDistance =
-            util::maplibre::GetMapDistance(params).value() / 1852.0f;
-         gl.glUniform1f(p->uMapDistanceLocation_,
-                        static_cast<float>(mapDistance));
+         units::length::nautical_miles<float> mapDistance =
+            util::maplibre::GetMapDistance(params);
+         gl.glUniform1f(p->uMapDistanceLocation_, mapDistance.value());
       }
       else
       {
@@ -311,9 +308,9 @@ void PlacefilePolygons::Impl::Tessellate(
    // Default color to "Color" statement
    boost::gil::rgba8_pixel_t lastColor = di->color_;
 
-   // TODO: nautical miles
-   currentThreshold_ =
-      static_cast<GLint>(std::roundf(di->threshold_.value() / 1852.0f));
+   // Current threshold
+   units::length::nautical_miles<double> threshold = di->threshold_;
+   currentThreshold_ = static_cast<GLint>(std::round(threshold.value()));
 
    gluTessBeginPolygon(tessellator_, this);
 
diff --git a/scwx-qt/source/scwx/qt/map/placefile_layer.cpp b/scwx-qt/source/scwx/qt/map/placefile_layer.cpp
index 70db64a5..ca98bdfa 100644
--- a/scwx-qt/source/scwx/qt/map/placefile_layer.cpp
+++ b/scwx-qt/source/scwx/qt/map/placefile_layer.cpp
@@ -8,7 +8,6 @@
 #include <scwx/common/geographic.hpp>
 #include <scwx/util/logger.hpp>
 
-#include <boost/units/base_units/metric/nautical_mile.hpp>
 #include <fmt/format.h>
 #include <imgui.h>
 #include <mbgl/util/constants.hpp>
@@ -69,7 +68,7 @@ public:
    bool          thresholded_ {true};
    ImFont*       monospaceFont_ {};
 
-   boost::units::quantity<boost::units::si::length> mapDistance_ {};
+   units::length::nautical_miles<double> mapDistance_ {};
 
    std::shared_ptr<gl::draw::PlacefileIcons>    placefileIcons_;
    std::shared_ptr<gl::draw::PlacefilePolygons> placefilePolygons_;
diff --git a/scwx-qt/source/scwx/qt/model/alert_model.cpp b/scwx-qt/source/scwx/qt/model/alert_model.cpp
index 4cadff42..e44e2a17 100644
--- a/scwx-qt/source/scwx/qt/model/alert_model.cpp
+++ b/scwx-qt/source/scwx/qt/model/alert_model.cpp
@@ -1,3 +1,5 @@
+#define NOMINMAX
+
 #include <scwx/qt/model/alert_model.hpp>
 #include <scwx/qt/config/county_database.hpp>
 #include <scwx/qt/manager/text_event_manager.hpp>
diff --git a/scwx-qt/source/scwx/qt/util/geographic_lib.cpp b/scwx-qt/source/scwx/qt/util/geographic_lib.cpp
index 84ae9e66..0496d88a 100644
--- a/scwx-qt/source/scwx/qt/util/geographic_lib.cpp
+++ b/scwx-qt/source/scwx/qt/util/geographic_lib.cpp
@@ -18,15 +18,14 @@ const ::GeographicLib::Geodesic& DefaultGeodesic()
    return geodesic_;
 }
 
-boost::units::quantity<boost::units::si::length>
+units::length::meters<double>
 GetDistance(double lat1, double lon1, double lat2, double lon2)
 {
    double distance;
    util::GeographicLib::DefaultGeodesic().Inverse(
       lat1, lon1, lat2, lon2, distance);
 
-   return static_cast<boost::units::quantity<boost::units::si::length>>(
-      distance * boost::units::si::meter_base_unit::unit_type());
+   return units::length::meters<double> {distance};
 }
 
 } // namespace GeographicLib
diff --git a/scwx-qt/source/scwx/qt/util/geographic_lib.hpp b/scwx-qt/source/scwx/qt/util/geographic_lib.hpp
index c3e74ef9..d93dce2b 100644
--- a/scwx-qt/source/scwx/qt/util/geographic_lib.hpp
+++ b/scwx-qt/source/scwx/qt/util/geographic_lib.hpp
@@ -1,8 +1,7 @@
 #pragma once
 
 #include <GeographicLib/Geodesic.hpp>
-#include <boost/units/quantity.hpp>
-#include <boost/units/systems/si/length.hpp>
+#include <units/length.h>
 
 namespace scwx
 {
@@ -30,7 +29,7 @@ const ::GeographicLib::Geodesic& DefaultGeodesic();
  *
  * @return distance between point 1 and point 2
  */
-boost::units::quantity<boost::units::si::length>
+units::length::meters<double>
 GetDistance(double lat1, double lon1, double lat2, double lon2);
 
 } // namespace GeographicLib
diff --git a/scwx-qt/source/scwx/qt/util/maplibre.cpp b/scwx-qt/source/scwx/qt/util/maplibre.cpp
index 5b3f331e..8cde77ca 100644
--- a/scwx-qt/source/scwx/qt/util/maplibre.cpp
+++ b/scwx-qt/source/scwx/qt/util/maplibre.cpp
@@ -12,11 +12,12 @@ namespace util
 namespace maplibre
 {
 
-boost::units::quantity<boost::units::si::length>
+units::length::meters<double>
 GetMapDistance(const QMapLibreGL::CustomLayerRenderParameters& params)
 {
-   return QMapLibreGL::metersPerPixelAtLatitude(params.latitude, params.zoom) *
-          (params.width + params.height) / 2.0 * boost::units::si::meters;
+   return units::length::meters<double>(
+      QMapLibreGL::metersPerPixelAtLatitude(params.latitude, params.zoom) *
+      (params.width + params.height) / 2.0);
 }
 
 glm::vec2 LatLongToScreenCoordinate(const QMapLibreGL::Coordinate& coordinate)
diff --git a/scwx-qt/source/scwx/qt/util/maplibre.hpp b/scwx-qt/source/scwx/qt/util/maplibre.hpp
index 65aa4409..37d205eb 100644
--- a/scwx-qt/source/scwx/qt/util/maplibre.hpp
+++ b/scwx-qt/source/scwx/qt/util/maplibre.hpp
@@ -1,9 +1,8 @@
 #pragma once
 
 #include <QMapLibreGL/types.hpp>
-#include <boost/units/quantity.hpp>
-#include <boost/units/systems/si/length.hpp>
 #include <glm/gtc/type_ptr.hpp>
+#include <units/length.h>
 
 namespace scwx
 {
@@ -14,7 +13,7 @@ namespace util
 namespace maplibre
 {
 
-boost::units::quantity<boost::units::si::length>
+units::length::meters<double>
 GetMapDistance(const QMapLibreGL::CustomLayerRenderParameters& params);
 glm::vec2 LatLongToScreenCoordinate(const QMapLibreGL::Coordinate& coordinate);
 
diff --git a/wxdata/include/scwx/gr/placefile.hpp b/wxdata/include/scwx/gr/placefile.hpp
index 8330aa4f..10ea2802 100644
--- a/wxdata/include/scwx/gr/placefile.hpp
+++ b/wxdata/include/scwx/gr/placefile.hpp
@@ -9,9 +9,8 @@
 #include <vector>
 
 #include <boost/gil/typedefs.hpp>
-#include <boost/units/quantity.hpp>
-#include <boost/units/systems/angle/degrees.hpp>
-#include <boost/units/systems/si/length.hpp>
+#include <units/angle.h>
+#include <units/length.h>
 
 namespace scwx
 {
@@ -71,22 +70,22 @@ public:
 
    struct DrawItem
    {
-      ItemType itemType_ {ItemType::Unknown};
-      boost::units::quantity<boost::units::si::length> threshold_ {};
+      ItemType                              itemType_ {ItemType::Unknown};
+      units::length::nautical_miles<double> threshold_ {};
    };
 
    struct IconDrawItem : DrawItem
    {
       IconDrawItem() { itemType_ = ItemType::Icon; }
 
-      double                                                    latitude_ {};
-      double                                                    longitude_ {};
-      double                                                    x_ {};
-      double                                                    y_ {};
-      boost::units::quantity<boost::units::degree::plane_angle> angle_ {};
-      std::size_t fileNumber_ {0u};
-      std::size_t iconNumber_ {0u};
-      std::string hoverText_ {};
+      double                 latitude_ {};
+      double                 longitude_ {};
+      double                 x_ {};
+      double                 y_ {};
+      units::degrees<double> angle_ {};
+      std::size_t            fileNumber_ {0u};
+      std::size_t            iconNumber_ {0u};
+      std::string            hoverText_ {};
    };
 
    struct TextDrawItem : DrawItem
diff --git a/wxdata/source/scwx/gr/placefile.cpp b/wxdata/source/scwx/gr/placefile.cpp
index 1725dd64..5c86f319 100644
--- a/wxdata/source/scwx/gr/placefile.cpp
+++ b/wxdata/source/scwx/gr/placefile.cpp
@@ -9,7 +9,8 @@
 #include <unordered_map>
 
 #include <boost/algorithm/string.hpp>
-#include <boost/units/base_units/metric/nautical_mile.hpp>
+
+using namespace units::literals;
 
 namespace scwx
 {
@@ -58,11 +59,10 @@ public:
    std::chrono::seconds refresh_ {-1};
 
    // Parsing state
-   boost::units::quantity<boost::units::si::length> threshold_ {
-      999.0 * boost::units::metric::nautical_mile_base_unit::unit_type()};
-   boost::gil::rgba8_pixel_t color_ {255, 255, 255, 255};
-   ColorMode                 colorMode_ {ColorMode::RGBA};
-   std::vector<Object>       objectStack_ {};
+   units::length::nautical_miles<double> threshold_ {999.0_nmi};
+   boost::gil::rgba8_pixel_t             color_ {255, 255, 255, 255};
+   ColorMode                             colorMode_ {ColorMode::RGBA};
+   std::vector<Object>                   objectStack_ {};
    DrawingStatement          currentStatement_ {DrawingStatement::Standard};
    std::shared_ptr<DrawItem> currentDrawItem_ {nullptr};
    std::vector<PolygonDrawItem::Element> currentPolygonContour_ {};
@@ -245,9 +245,7 @@ void Placefile::Impl::ProcessLine(const std::string& line)
       if (tokenList.size() >= 1)
       {
          threshold_ =
-            static_cast<boost::units::quantity<boost::units::si::length>>(
-               std::stod(tokenList[0]) *
-               boost::units::metric::nautical_mile_base_unit::unit_type());
+            units::length::nautical_miles<double>(std::stod(tokenList[0]));
       }
    }
    else if (boost::istarts_with(line, timeRangeKey_))
@@ -384,10 +382,7 @@ void Placefile::Impl::ProcessLine(const std::string& line)
                        di->x_,
                        di->y_);
 
-         di->angle_ = static_cast<
-            boost::units::quantity<boost::units::degree::plane_angle>>(
-            std::stod(tokenList[2]) *
-            boost::units::angle::degree_base_unit::unit_type());
+         di->angle_ = units::angle::degrees<double>(std::stod(tokenList[2]));
 
          di->fileNumber_ = std::stoul(tokenList[3]);
          di->iconNumber_ = std::stoul(tokenList[4]);
diff --git a/wxdata/wxdata.cmake b/wxdata/wxdata.cmake
index a9a8dce7..38ffd1b0 100644
--- a/wxdata/wxdata.cmake
+++ b/wxdata/wxdata.cmake
@@ -259,7 +259,8 @@ target_link_libraries(wxdata PUBLIC aws-cpp-sdk-core
                                     aws-cpp-sdk-s3
                                     cpr::cpr
                                     LibXml2::LibXml2
-                                    spdlog::spdlog)
+                                    spdlog::spdlog
+                                    units::units)
 target_link_libraries(wxdata INTERFACE Boost::iostreams
                                        BZip2::BZip2
                                        hsluv-c)