feat(new tool): Running Pace Calculator

Fix #400 (and #413)

Author: sharevb

package.json

@@ -317,6 +317,7 @@
     "riimut": "^0.9.1",
     "roboto-base64": "^0.1.2",
     "rtf-stream-parser": "^3.8.1",
+    "run-pace": "^2.2.0",
     "safe-license-list": "^0.1.2",
     "sandybox": "^1.1.2",
     "sanitize-html": "^2.17.0",
@@ -467,7 +468,8 @@
     },
     "patchedDependencies": {
       "node-forge@1.4.0": "patches/node-forge@1.4.0.patch",
-      "esm-potrace-wasm": "patches/esm-potrace-wasm.patch"
+      "esm-potrace-wasm": "patches/esm-potrace-wasm.patch",
+      "run-pace": "patches/run-pace.patch"
     }
   },
   "scarfSettings": {

patches/run-pace.patch

@@ -0,0 +1,12 @@
+diff --git a/lib/run-pace.js b/lib/run-pace.js
+index 2b20a32ff4b5712016dd869a734ff25f730cdb12..9b9b72187e6675db6b295a827f2293950d12a111 100644
+--- a/lib/run-pace.js
++++ b/lib/run-pace.js
+@@ -119,7 +119,3 @@ function removeTrailingZeroes(number) {
+ function removeLeadingZero(number) {
+   return number.replace(/^0/, "");
+ }
+-
+-function zeroPad(number) {
+-  return `0${number}`.slice(-2);
+-}

pnpm-lock.yaml

@@ -0,0 +1,13 @@
+import { Run } from '@vicons/tabler';
+import { defineTool } from '../tool';
+
+export const tool = defineTool({
+  name: 'Running Pace Calculator',
+  path: '/running-pace-calculator',
+  description: 'Calculate your running pace, estimate your finish times for popular races, break down splits, and find your training zones.',
+  keywords: ['running', 'pace', 'calculator'],
+  component: () => import('./running-pace-calculator.vue'),
+  icon: Run,
+  createdAt: new Date('2026-06-21'),
+  category: 'Data',
+});

src/tools/running-pace-calculator/index.ts

@@ -0,0 +1,26 @@
+declare module 'run-pace' {
+    export function calculatePace(options: {
+        time: string;
+        length: string;
+        imperial?: boolean;
+        metric?: boolean;
+        speed?: boolean;
+    }): string;
+    export function calculateLength(options: {
+        time: string;
+        pace: string;
+        imperial?: boolean;
+        metric?: boolean;
+    }): string;
+    export function calculateTime(options: {
+        length: string;
+        pace: string;
+        imperial?: boolean;
+        metric?: boolean;
+    }): string;
+    export function paceToSpeed(options: {
+        pace: string;
+        imperial?: boolean;
+        metric?: boolean;
+    }): string;
+}

src/tools/running-pace-calculator/run-pace.d.ts

@@ -0,0 +1,125 @@
+<script setup lang="ts">
+import * as runPace from 'run-pace';
+
+// Inputs
+const length = ref<string>('');
+const time = ref<string>('');
+const pace = ref<string>('');
+
+// Options
+const unit = ref<'km' | 'mile'>('km');
+const speed = ref<boolean>(false);
+
+// Output
+const result = ref<string>('');
+const resultType = ref<string>('');
+const error = ref<string>('');
+
+function calculateStuff() {
+  result.value = '';
+  error.value = '';
+
+  const options: any = {
+    length: length.value,
+    time: time.value,
+    pace: pace.value,
+  };
+
+  // Unit selection
+  if (unit.value === 'km') {
+    options.metric = true;
+  }
+  if (unit.value === 'mile') {
+    options.imperial = true;
+  }
+
+  options.speed = speed.value;
+
+  try {
+    if (options.time && options.length && options.pace) {
+      throw new Error(
+        'Only two of "time", "length" and "pace" may be provided at any time',
+      );
+    }
+    else if (options.time && options.pace) {
+      if (options.speed) {
+        throw new Error('Speed is only valid when (only) pace is given or calculated');
+      }
+      resultType.value = 'Length';
+      result.value = `${runPace.calculateLength(options)}`;
+    }
+    else if (options.time && options.length) {
+      const label = options.speed ? 'Speed' : 'Pace';
+      resultType.value = label;
+      result.value = `${runPace.calculatePace(options)}`;
+    }
+    else if (options.pace && options.length) {
+      if (options.speed) {
+        throw new Error('Speed is only valid when (only) pace is given or calculated');
+      }
+      resultType.value = 'Time';
+      result.value = `${runPace.calculateTime(options)}`;
+    }
+    else if (options.pace && options.speed) {
+      resultType.value = 'Speed';
+      result.value = `${runPace.paceToSpeed(options)}`;
+    }
+    else {
+      throw new Error(
+        'Two of "time", "length" and "pace" must be provided.\nSpeed is only valid when pace is given or calculated.',
+      );
+    }
+  }
+  catch (e: any) {
+    error.value = e.message;
+  }
+}
+</script>
+
+<template>
+  <div>
+    <NForm label-placement="left" label-width="70px">
+      <NFormItem label="Length:">
+        <NInput v-model:value="length" placeholder="e.g. 10km or 100m" clearable />
+      </NFormItem>
+
+      <NFormItem label="Time:">
+        <NInput v-model:value="time" placeholder="e.g. 45:00 or 45min or 1h30..." clearable />
+      </NFormItem>
+
+      <NFormItem label="Pace:">
+        <NInput v-model:value="pace" placeholder="e.g. 4:30/km" clearable />
+      </NFormItem>
+
+      <n-space justify="center">
+        <NFormItem label="Unit:">
+          <NRadioGroup v-model:value="unit">
+            <NRadio value="km">
+              km
+            </NRadio>
+            <NRadio value="mile">
+              mile
+            </NRadio>
+          </NRadioGroup>
+        </NFormItem>
+        <NFormItem label="Output speed in instead of pace:" label-width="auto">
+          <NSwitch v-model:value="speed" />
+        </NFormItem>
+      </n-space>
+    </NForm>
+
+    <n-space justify="center" mb-2>
+      <NButton type="primary" @click="calculateStuff">
+        Calculate
+      </NButton>
+    </n-space>
+
+    <c-alert v-if="error">
+      {{ error }}
+    </c-alert>
+
+    <c-card v-if="result" title="Result">
+      <input-copyable :label="`${resultType}:`" label-position="left" :value="result" />
+    </c-card>
+  </div>
+</template>