diff --git a/src/components/Earn.tsx b/src/components/Earn.tsx
index c934b69d..1c0dab1f 100644
--- a/src/components/Earn.tsx
+++ b/src/components/Earn.tsx
@@ -6,8 +6,14 @@ import { TFunction } from 'i18next'
 import { useSettings } from '../context/SettingsContext'
 import { CurrentWallet, useCurrentWalletInfo, useReloadCurrentWalletInfo, WalletInfo } from '../context/WalletContext'
 import { useServiceInfo, useReloadServiceInfo, Offer } from '../context/ServiceInfoContext'
-import { factorToPercentage, isAbsoluteOffer, isRelativeOffer, isValidNumber, percentageToFactor } from '../utils'
-import { JM_DUST_THRESHOLD } from '../constants/jm'
+import {
+  calcOfferMinsizeMax,
+  factorToPercentage,
+  isAbsoluteOffer,
+  isRelativeOffer,
+  isValidNumber,
+  percentageToFactor,
+} from '../utils'
 import {
   OFFER_FEE_ABS_MIN,
   OFFER_FEE_REL_MAX,
@@ -220,20 +226,9 @@ const EarnForm = ({
 }: EarnFormProps) => {
   const { t } = useTranslation()
 
-  const maxAvailableBalanceInJar = useMemo(() => {
-    return Math.max(
-      0,
-      Math.max(
-        ...Object.values(walletInfo?.balanceSummary.accountBalances || []).map(
-          (it) => it.calculatedAvailableBalanceInSats,
-        ),
-      ),
-    )
-  }, [walletInfo])
-
   const offerMinsizeMax = useMemo(() => {
-    return Math.max(0, maxAvailableBalanceInJar - JM_DUST_THRESHOLD)
-  }, [maxAvailableBalanceInJar])
+    return walletInfo === undefined ? 0 : calcOfferMinsizeMax(walletInfo.balanceSummary.accountBalances)
+  }, [walletInfo])
 
   const validate = (values: EarnFormValues) => {
     const errors = {} as FormikErrors<EarnFormValues>
@@ -277,15 +272,7 @@ const EarnForm = ({
   }
 
   return (
-    <Formik
-      initialValues={initialValues}
-      validate={validate}
-      onSubmit={onSubmit}
-      validateOnMount={true}
-      initialTouched={{
-        minsize: true,
-      }}
-    >
+    <Formik initialValues={initialValues} validate={validate} onSubmit={onSubmit}>
       {(props) => {
         const { handleSubmit, setFieldValue, handleBlur, values, touched, errors, isSubmitting } = props
         const minsizeField = props.getFieldProps<AmountValue>('minsize')
diff --git a/src/utils.test.ts b/src/utils.test.ts
index 937199ed..6662127d 100644
--- a/src/utils.test.ts
+++ b/src/utils.test.ts
@@ -7,6 +7,7 @@ import {
   formatSats,
   formatBtc,
   formatBtcDisplayValue,
+  calcOfferMinsizeMax,
 } from './utils'
 
 describe('shortenStringMiddle', () => {
@@ -180,3 +181,41 @@ describe('formatBtcDisplayValue', () => {
     expect(formatBtcDisplayValue(123456789, { withSymbol: true })).toBe('₿ 1.23 456 789')
   })
 })
+
+describe('calcOfferMinsizeMax', () => {
+  it('should calc offer minsize based on wallet balance', () => {
+    expect(calcOfferMinsizeMax({})).toBe(0)
+    expect(
+      calcOfferMinsizeMax(
+        {
+          '0': {
+            accountIndex: 0,
+            calculatedTotalBalanceInSats: 21,
+            calculatedAvailableBalanceInSats: 21,
+            calculatedFrozenOrLockedBalanceInSats: 0,
+          },
+        },
+        0,
+      ),
+    ).toBe(21)
+    expect(
+      calcOfferMinsizeMax(
+        {
+          '0': {
+            accountIndex: 0,
+            calculatedTotalBalanceInSats: 42,
+            calculatedAvailableBalanceInSats: 41,
+            calculatedFrozenOrLockedBalanceInSats: 1,
+          },
+          '1': {
+            accountIndex: 1,
+            calculatedTotalBalanceInSats: 42_000,
+            calculatedAvailableBalanceInSats: 1,
+            calculatedFrozenOrLockedBalanceInSats: 41_999,
+          },
+        },
+        21,
+      ),
+    ).toBe(20)
+  })
+})
diff --git a/src/utils.ts b/src/utils.ts
index 9a2db657..526c6c41 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,4 +1,6 @@
-import { AmountSats, OfferType, WalletFileName } from './libs/JmWalletApi'
+import { JM_DUST_THRESHOLD } from './constants/jm'
+import type { AccountBalances } from './context/BalanceSummary'
+import type { AmountSats, OfferType, WalletFileName } from './libs/JmWalletApi'
 
 const BTC_FORMATTER = new Intl.NumberFormat('en-US', {
   minimumIntegerDigits: 1,
@@ -135,3 +137,15 @@ export const setIntervalDebounced = (
     )
   })()
 }
+
+const calcMaxAvailableBalanceInJar = (accountBalances: AccountBalances) => {
+  return Math.max(0, Math.max(...Object.values(accountBalances || []).map((it) => it.calculatedAvailableBalanceInSats)))
+}
+
+export const calcOfferMinsizeMax = (
+  accountBalances: AccountBalances,
+  minBufferAmount: AmountSats = JM_DUST_THRESHOLD,
+) => {
+  const maxAvailableBalanceInJar = calcMaxAvailableBalanceInJar(accountBalances)
+  return Math.max(0, maxAvailableBalanceInJar - minBufferAmount)
+}