diff --git a/packages/page-staking/src/Targets/index.tsx b/packages/page-staking/src/Targets/index.tsx
index c6e4d0dc5c..a721126099 100644
--- a/packages/page-staking/src/Targets/index.tsx
+++ b/packages/page-staking/src/Targets/index.tsx
@@ -110,6 +110,7 @@ function Targets ({ className = '', ownStashes, targets: { calcWith, lastReward,
         className='balanceInput'
         help={t<string>('The amount that will be used on a per-validator basis to calculate profits for that validator.')}
         isFull
+        isZeroable={false}
         label={t<string>('amount to use for estimation')}
         onChange={setCalcWith}
         value={calcWith}
diff --git a/packages/page-staking/src/useSortedTargets.ts b/packages/page-staking/src/useSortedTargets.ts
index b8dc795a3e..202b5afd60 100644
--- a/packages/page-staking/src/useSortedTargets.ts
+++ b/packages/page-staking/src/useSortedTargets.ts
@@ -84,9 +84,9 @@ function extractInfo (allAccounts: string[], amount: BN = baseBalance(), elected
         : (prefs as ValidatorPrefs).commission.unwrap().mul(perValidatorReward).div(PERBILL);
       const key = accountId.toString();
       const rewardSplit = perValidatorReward.sub(validatorPayment);
-      const rewardPayout = rewardSplit.gtn(0)
-        ? amount.mul(rewardSplit).div(amount.add(bondTotal))
-        : BN_ZERO;
+      const rewardPayout = amount.isZero() || rewardSplit.isZero()
+        ? BN_ZERO
+        : amount.mul(rewardSplit).div(amount.add(bondTotal));
       const isNominating = exposure.others.reduce((isNominating, indv): boolean => {
         const nominator = indv.who.toString();