diff --git a/app/components/ContributionAmountField.vue b/app/components/ContributionAmountField.vue
new file mode 100644
index 0000000..64485d6
--- /dev/null
+++ b/app/components/ContributionAmountField.vue
@@ -0,0 +1,297 @@
+<template>
+  <div class="contribution-amount-field">
+    <div v-if="allowCadenceChange" class="form-group">
+      <label class="form-label">How often</label>
+      <div class="cadence-radios">
+        <div class="circle-radio">
+          <input
+            :id="`${uid}-cadence-monthly`"
+            type="radio"
+            :name="`${uid}-cadence`"
+            value="monthly"
+            :checked="cadence === 'monthly'"
+            @change="onCadenceChange('monthly')"
+          >
+          <label :for="`${uid}-cadence-monthly`">
+            <span class="circle-label-name">Per Month</span>
+          </label>
+        </div>
+        <div class="circle-radio">
+          <input
+            :id="`${uid}-cadence-annual`"
+            type="radio"
+            :name="`${uid}-cadence`"
+            value="annual"
+            :checked="cadence === 'annual'"
+            @change="onCadenceChange('annual')"
+          >
+          <label :for="`${uid}-cadence-annual`">
+            <span class="circle-label-name">Per Year</span>
+          </label>
+        </div>
+      </div>
+    </div>
+
+    <div class="form-group">
+      <label class="form-label" :for="`${uid}-amount`">Contribution</label>
+      <div class="contribution-input-row">
+        <span class="contribution-currency">$</span>
+        <input
+          :id="`${uid}-amount`"
+          :value="modelValue"
+          type="number"
+          min="0"
+          step="1"
+          inputmode="numeric"
+          class="contribution-input"
+          @input="onAmountInput"
+        >
+      </div>
+      <div
+        class="contribution-presets"
+        role="group"
+        aria-label="Suggested amounts"
+      >
+        <button
+          v-for="preset in presetChips"
+          :key="preset.amount"
+          type="button"
+          class="contribution-preset-chip"
+          :class="{ active: numericAmount === preset.amount }"
+          @click="selectPreset(preset.amount)"
+        >
+          ${{ preset.amount }}
+        </button>
+      </div>
+      <p v-if="guidanceLabel" class="contribution-guidance">
+        {{ guidanceLabel }}
+      </p>
+      <p v-if="showSoftMax" class="contribution-soft-max">
+        Whoa, that's a lot. Are you sure that's the amount you meant?
+      </p>
+    </div>
+
+    <div v-if="showSummary && numericAmount > 0" class="form-group">
+      <div class="billing-summary">
+        <p class="billing-summary-line">
+          You'll be charged <strong>${{ numericAmount }} today</strong>.
+        </p>
+        <p class="billing-summary-line">
+          Then <strong>${{ numericAmount }}</strong>
+          {{ cadence === 'annual' ? 'at each annual renewal.' : 'each month.' }}
+        </p>
+        <p v-if="summaryNote" class="billing-summary-line billing-summary-note">
+          {{ summaryNote }}
+        </p>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { computed, useId } from 'vue'
+import {
+  CONTRIBUTION_PRESETS,
+  getGuidanceLabel,
+} from '~/config/contributions.js'
+
+const props = defineProps({
+  modelValue: { type: Number, required: true },
+  cadence: { type: String, required: true },
+  allowCadenceChange: { type: Boolean, default: true },
+  showSummary: { type: Boolean, default: true },
+  summaryNote: { type: String, default: '' },
+})
+
+const emit = defineEmits(['update:modelValue', 'update:cadence'])
+
+const uid = useId()
+
+const numericAmount = computed(() => {
+  const n = Number(props.modelValue)
+  return Number.isFinite(n) ? n : 0
+})
+
+const monthlyEquivalent = computed(() =>
+  props.cadence === 'annual' ? numericAmount.value / 12 : numericAmount.value,
+)
+
+const presetChips = computed(() =>
+  CONTRIBUTION_PRESETS.map((p) => ({
+    amount: props.cadence === 'annual' ? p.amount * 12 : p.amount,
+    label: p.label,
+  })),
+)
+
+const guidanceLabel = computed(() => getGuidanceLabel(monthlyEquivalent.value))
+
+const showSoftMax = computed(() => monthlyEquivalent.value > 500)
+
+const onAmountInput = (event) => {
+  const raw = event.target.value
+  if (raw === '') {
+    emit('update:modelValue', 0)
+    return
+  }
+  const n = Number(raw)
+  emit('update:modelValue', Number.isFinite(n) ? n : 0)
+}
+
+const selectPreset = (amount) => {
+  emit('update:modelValue', amount)
+}
+
+// Annual→monthly snap: floor(annual/12)*12 keeps the amount cleanly divisible
+// before we divide, so toggling cadences never leaves fractional dollars.
+const onCadenceChange = (newCadence) => {
+  if (newCadence === props.cadence) return
+  const current = numericAmount.value
+  let next = current
+  if (newCadence === 'annual') {
+    next = current * 12
+  } else {
+    next = Math.floor(current / 12)
+  }
+  emit('update:cadence', newCadence)
+  emit('update:modelValue', next)
+}
+</script>
+
+<style scoped>
+.form-group {
+  margin-bottom: 16px;
+}
+.form-group:last-child {
+  margin-bottom: 0;
+}
+.form-label {
+  display: block;
+  margin-bottom: 6px;
+  font-size: 10px;
+  letter-spacing: 0.1em;
+  text-transform: uppercase;
+  color: var(--text-faint);
+}
+
+.cadence-radios {
+  display: grid;
+  grid-template-columns: repeat(2, 1fr);
+  gap: 10px;
+}
+.circle-radio {
+  position: relative;
+}
+.circle-radio input {
+  position: absolute;
+  opacity: 0;
+  width: 0;
+  height: 0;
+}
+.circle-radio label {
+  display: block;
+  border: 1px dashed var(--border);
+  padding: 14px 12px;
+  cursor: pointer;
+  transition: all 0.2s;
+  text-align: center;
+}
+.circle-radio label:hover {
+  border-color: var(--candle-faint);
+}
+.circle-radio input:checked + label {
+  border-style: solid;
+  border-color: var(--candle);
+}
+.circle-radio input:checked + label .circle-label-name {
+  color: var(--text-bright);
+}
+.circle-label-name {
+  font-size: 12px;
+  color: var(--text-dim);
+  display: block;
+}
+
+.contribution-input-row {
+  display: flex;
+  align-items: center;
+  gap: 0.25rem;
+}
+.contribution-currency {
+  font-weight: 600;
+}
+.contribution-input {
+  flex: 1;
+  padding: 0.5rem 0.75rem;
+  background: var(--input-bg);
+  border: 1px solid var(--parch);
+  font-family: 'Commit Mono', monospace;
+  font-size: 1rem;
+  color: var(--text-bright);
+}
+.contribution-input:focus {
+  outline: none;
+  border-color: var(--candle);
+}
+
+.contribution-presets {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.5rem;
+  margin-top: 0.5rem;
+}
+.contribution-preset-chip {
+  padding: 0.25rem 0.75rem;
+  background: transparent;
+  border: 1px dashed var(--parch);
+  font-family: 'Commit Mono', monospace;
+  font-size: 0.875rem;
+  cursor: pointer;
+  color: var(--text);
+}
+.contribution-preset-chip:hover {
+  border-style: solid;
+  border-color: var(--candle);
+}
+.contribution-preset-chip.active {
+  border-style: solid;
+  border-color: var(--candle);
+  background: var(--parch);
+  color: var(--text-bright);
+}
+
+.contribution-guidance {
+  margin-top: 0.5rem;
+  font-size: 0.875rem;
+  font-style: italic;
+  color: var(--text);
+}
+.contribution-soft-max {
+  margin-top: 0.5rem;
+  font-size: 0.875rem;
+  font-style: italic;
+  color: var(--ember);
+}
+
+.billing-summary {
+  padding: 12px 16px;
+  border: 1px dashed var(--border);
+  background: var(--surface);
+}
+.billing-summary-line {
+  font-size: 13px;
+  color: var(--text);
+  line-height: 1.5;
+  margin: 0;
+}
+.billing-summary-line + .billing-summary-line {
+  margin-top: 4px;
+}
+.billing-summary-line strong {
+  color: var(--text-bright);
+  font-weight: 600;
+}
+.billing-summary-note {
+  color: var(--text-dim);
+  font-style: italic;
+}
+</style>