diff --git a/internal/core/repeaters.go b/internal/core/repeaters.go
index b2e5ee7..4dc25eb 100644
--- a/internal/core/repeaters.go
+++ b/internal/core/repeaters.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"html/template"
 	"image/color"
+	"math"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -175,15 +176,17 @@ func (s *Handlers) handleAddRepeater(w http.ResponseWriter, r *http.Request) {
 }
 
 // parseRadioForm reads and validates the radio fields from a repeater form.
+// Frequency and bandwidth are entered in MHz/kHz (matching the region presets)
+// and stored as Hz.
 func parseRadioForm(r *http.Request) (freq, bw int64, sf, cr int16, ok bool) {
-	f, e1 := strconv.ParseInt(r.FormValue("radio_freq_hz"), 10, 64)
-	b, e2 := strconv.ParseInt(r.FormValue("radio_bw_hz"), 10, 64)
+	mhz, e1 := strconv.ParseFloat(r.FormValue("radio_freq_mhz"), 64)
+	khz, e2 := strconv.ParseFloat(r.FormValue("radio_bw_khz"), 64)
 	s, e3 := strconv.ParseInt(r.FormValue("radio_sf"), 10, 16)
 	c, e4 := strconv.ParseInt(r.FormValue("radio_cr"), 10, 16)
-	if e1 != nil || e2 != nil || e3 != nil || e4 != nil || f <= 0 || b <= 0 {
+	if e1 != nil || e2 != nil || e3 != nil || e4 != nil || mhz <= 0 || khz <= 0 {
 		return 0, 0, 0, 0, false
 	}
-	return f, b, int16(s), int16(c), true
+	return int64(math.Round(mhz * 1e6)), int64(math.Round(khz * 1e3)), int16(s), int16(c), true
 }
 
 // pageEditRepeater shows the edit form for an owned repeater.
diff --git a/internal/core/templates/add_repeater.html b/internal/core/templates/add_repeater.html
index dd09f02..7155be8 100644
--- a/internal/core/templates/add_repeater.html
+++ b/internal/core/templates/add_repeater.html
@@ -93,8 +93,8 @@
         </select>
       </div>
       <div class="row g-2">
-        <div class="col-6 col-md-3"><label class="form-label" for="radio_freq_hz">Freq (Hz)</label><input type="number" class="form-control" id="radio_freq_hz" name="radio_freq_hz" value="{{.Defaults.FreqHz}}" required></div>
-        <div class="col-6 col-md-3"><label class="form-label" for="radio_bw_hz">Bandwidth (Hz)</label><input type="number" class="form-control" id="radio_bw_hz" name="radio_bw_hz" value="{{.Defaults.BwHz}}" required></div>
+        <div class="col-6 col-md-3"><label class="form-label" for="radio_freq_mhz">Freq (MHz)</label><input type="number" step="0.001" class="form-control" id="radio_freq_mhz" name="radio_freq_mhz" value="{{mhz .Defaults.FreqHz}}" required></div>
+        <div class="col-6 col-md-3"><label class="form-label" for="radio_bw_khz">Bandwidth (kHz)</label><input type="number" step="0.1" class="form-control" id="radio_bw_khz" name="radio_bw_khz" value="{{khz .Defaults.BwHz}}" required></div>
         <div class="col-6 col-md-3"><label class="form-label" for="radio_sf">SF</label><input type="number" class="form-control" id="radio_sf" name="radio_sf" value="{{.Defaults.SF}}" min="5" max="12" required></div>
         <div class="col-6 col-md-3"><label class="form-label" for="radio_cr">CR</label><input type="number" class="form-control" id="radio_cr" name="radio_cr" value="{{.Defaults.CR}}" min="5" max="8" required></div>
       </div>
@@ -112,23 +112,45 @@
   </div>
 </div>
 <script>
+  // The form fields display MHz/kHz; preset data-* attributes are Hz-canonical.
+  var RADIO_FIELDS = ["radio_freq_mhz", "radio_bw_khz", "radio_sf", "radio_cr"];
+  function trim(n) { return String(Math.round(n * 1e6) / 1e6); } // drop float fuzz
+
+  // Seed the radio fields from the chosen preset. Fields stay editable — a
+  // preset is a starting point, not a lock.
   function applyRegion() {
     var sel = document.getElementById("region");
     var opt = sel.options[sel.selectedIndex];
-    var fields = ["radio_freq_hz", "radio_bw_hz", "radio_sf", "radio_cr"].map(function (id) {
-      return document.getElementById(id);
-    });
-    if (opt.dataset.freq) {
-      fields[0].value = opt.dataset.freq;
-      fields[1].value = opt.dataset.bw;
-      fields[2].value = opt.dataset.sf;
-      fields[3].value = opt.dataset.cr;
-      fields.forEach(function (el) { el.readOnly = true; });
-    } else {
-      fields.forEach(function (el) { el.readOnly = false; });
-    }
+    if (!opt.dataset.freq) return; // "Custom" — leave the current values alone
+    document.getElementById("radio_freq_mhz").value = trim(opt.dataset.freq / 1e6);
+    document.getElementById("radio_bw_khz").value = trim(opt.dataset.bw / 1e3);
+    document.getElementById("radio_sf").value = opt.dataset.sf;
+    document.getElementById("radio_cr").value = opt.dataset.cr;
   }
-  applyRegion();
+
+  // When a field is edited by hand, point the dropdown at whichever preset now
+  // matches (or "Custom" if none do), so it always reflects the actual values.
+  // Compare in Hz so display rounding can't cause a spurious mismatch.
+  function syncPreset() {
+    var sel = document.getElementById("region");
+    var freqHz = Math.round(parseFloat(document.getElementById("radio_freq_mhz").value) * 1e6);
+    var bwHz = Math.round(parseFloat(document.getElementById("radio_bw_khz").value) * 1e3);
+    var sf = document.getElementById("radio_sf").value;
+    var cr = document.getElementById("radio_cr").value;
+    for (var i = 0; i < sel.options.length; i++) {
+      var o = sel.options[i];
+      if (o.dataset.freq && +o.dataset.freq === freqHz && +o.dataset.bw === bwHz &&
+          o.dataset.sf === sf && o.dataset.cr === cr) {
+        sel.value = o.value;
+        return;
+      }
+    }
+    sel.value = "custom";
+  }
+
+  RADIO_FIELDS.forEach(function (id) {
+    document.getElementById(id).addEventListener("input", syncPreset);
+  });
 </script>
 {{end}}
 </div>
diff --git a/internal/core/templates/confirm.html b/internal/core/templates/confirm.html
index 94af626..4a27bc1 100644
--- a/internal/core/templates/confirm.html
+++ b/internal/core/templates/confirm.html
@@ -16,7 +16,7 @@
       to verify it has access. This is optional — the repeater works either way.
     </p>
     <code class="pk">{{.Repeater.PublicKeyHex}}</code>
-    <div class="text-secondary small mt-2">{{.Repeater.RadioFreqHz}} Hz · BW {{.Repeater.RadioBwHz}} · SF{{.Repeater.RadioSF}} · CR{{.Repeater.RadioCR}}</div>
+    <div class="text-secondary small mt-2">{{mhz .Repeater.RadioFreqHz}} MHz · BW {{khz .Repeater.RadioBwHz}} · SF{{.Repeater.RadioSF}} · CR{{.Repeater.RadioCR}}</div>
 
     <div id="unsupported" class="alert alert-danger mt-3" role="alert" hidden>
       This browser does not support WebSerial. Use Chrome, Edge, or another Chromium-based browser over HTTPS or on localhost.
diff --git a/internal/core/templates/edit_repeater.html b/internal/core/templates/edit_repeater.html
index 475b663..4300cef 100644
--- a/internal/core/templates/edit_repeater.html
+++ b/internal/core/templates/edit_repeater.html
@@ -29,8 +29,8 @@
         </select>
       </div>
       <div class="row g-2">
-        <div class="col-6 col-md-3"><label class="form-label" for="radio_freq_hz">Freq (Hz)</label><input type="number" class="form-control" id="radio_freq_hz" name="radio_freq_hz" value="{{.Repeater.RadioFreqHz}}" required></div>
-        <div class="col-6 col-md-3"><label class="form-label" for="radio_bw_hz">Bandwidth (Hz)</label><input type="number" class="form-control" id="radio_bw_hz" name="radio_bw_hz" value="{{.Repeater.RadioBwHz}}" required></div>
+        <div class="col-6 col-md-3"><label class="form-label" for="radio_freq_mhz">Freq (MHz)</label><input type="number" step="0.001" class="form-control" id="radio_freq_mhz" name="radio_freq_mhz" value="{{mhz .Repeater.RadioFreqHz}}" required></div>
+        <div class="col-6 col-md-3"><label class="form-label" for="radio_bw_khz">Bandwidth (kHz)</label><input type="number" step="0.1" class="form-control" id="radio_bw_khz" name="radio_bw_khz" value="{{khz .Repeater.RadioBwHz}}" required></div>
         <div class="col-6 col-md-3"><label class="form-label" for="radio_sf">SF</label><input type="number" class="form-control" id="radio_sf" name="radio_sf" value="{{.Repeater.RadioSF}}" min="5" max="12" required></div>
         <div class="col-6 col-md-3"><label class="form-label" for="radio_cr">CR</label><input type="number" class="form-control" id="radio_cr" name="radio_cr" value="{{.Repeater.RadioCR}}" min="5" max="8" required></div>
       </div>
@@ -55,22 +55,44 @@
   </div>
 </div>
 <script>
+  // The form fields display MHz/kHz; preset data-* attributes are Hz-canonical.
+  var RADIO_FIELDS = ["radio_freq_mhz", "radio_bw_khz", "radio_sf", "radio_cr"];
+  function trim(n) { return String(Math.round(n * 1e6) / 1e6); } // drop float fuzz
+
+  // Seed the radio fields from the chosen preset. Fields stay editable — a
+  // preset is a starting point, not a lock.
   function applyRegion() {
     var sel = document.getElementById("region");
     var opt = sel.options[sel.selectedIndex];
-    var fields = ["radio_freq_hz", "radio_bw_hz", "radio_sf", "radio_cr"].map(function (id) {
-      return document.getElementById(id);
-    });
-    if (opt.dataset.freq) {
-      fields[0].value = opt.dataset.freq;
-      fields[1].value = opt.dataset.bw;
-      fields[2].value = opt.dataset.sf;
-      fields[3].value = opt.dataset.cr;
-      fields.forEach(function (el) { el.readOnly = true; });
-    } else {
-      fields.forEach(function (el) { el.readOnly = false; });
-    }
+    if (!opt.dataset.freq) return; // "Custom" — leave the current values alone
+    document.getElementById("radio_freq_mhz").value = trim(opt.dataset.freq / 1e6);
+    document.getElementById("radio_bw_khz").value = trim(opt.dataset.bw / 1e3);
+    document.getElementById("radio_sf").value = opt.dataset.sf;
+    document.getElementById("radio_cr").value = opt.dataset.cr;
   }
-  applyRegion();
+
+  // When a field is edited by hand, point the dropdown at whichever preset now
+  // matches (or "Custom" if none do), so it always reflects the actual values.
+  // Compare in Hz so display rounding can't cause a spurious mismatch.
+  function syncPreset() {
+    var sel = document.getElementById("region");
+    var freqHz = Math.round(parseFloat(document.getElementById("radio_freq_mhz").value) * 1e6);
+    var bwHz = Math.round(parseFloat(document.getElementById("radio_bw_khz").value) * 1e3);
+    var sf = document.getElementById("radio_sf").value;
+    var cr = document.getElementById("radio_cr").value;
+    for (var i = 0; i < sel.options.length; i++) {
+      var o = sel.options[i];
+      if (o.dataset.freq && +o.dataset.freq === freqHz && +o.dataset.bw === bwHz &&
+          o.dataset.sf === sf && o.dataset.cr === cr) {
+        sel.value = o.value;
+        return;
+      }
+    }
+    sel.value = "custom";
+  }
+
+  RADIO_FIELDS.forEach(function (id) {
+    document.getElementById(id).addEventListener("input", syncPreset);
+  });
 </script>
 {{end}}
diff --git a/internal/web/env.go b/internal/web/env.go
index 3d2bbe2..bb3473d 100644
--- a/internal/web/env.go
+++ b/internal/web/env.go
@@ -12,6 +12,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 
 	"github.com/go-chi/chi/v5"
@@ -117,8 +118,16 @@ func (e *Env) SetDefaultLayout(name string) { e.Renderer.defaultLayout = name }
 // NewRenderer parses the shared base layout (base.html + icons.html) and composes
 // each of the surface's own *.html pages onto it. Each page redefines the
 // content/title/header blocks, so every page gets its own cloned template set.
+// templateFuncs are helpers available to every page template. mhz/khz present
+// the Hz-canonical radio values in the human-readable units the region presets
+// use (MHz for frequency, kHz for bandwidth), formatted without trailing zeros.
+var templateFuncs = template.FuncMap{
+	"mhz": func(hz int64) string { return strconv.FormatFloat(float64(hz)/1e6, 'f', -1, 64) },
+	"khz": func(hz int64) string { return strconv.FormatFloat(float64(hz)/1e3, 'f', -1, 64) },
+}
+
 func NewRenderer(cfg *config.Config, surfaceTemplates fs.FS) (*Renderer, error) {
-	base, err := template.New("").ParseFS(sharedTemplatesFS, "templates/base.html", "templates/icons.html", "templates/org_tabs.html", "templates/repeater_tabs.html")
+	base, err := template.New("").Funcs(templateFuncs).ParseFS(sharedTemplatesFS, "templates/base.html", "templates/icons.html", "templates/org_tabs.html", "templates/repeater_tabs.html")
 	if err != nil {
 		return nil, err
 	}