diff --git a/common/util/format.ts b/common/util/format.ts
index c8d363d3..d7e381b4 100644
--- a/common/util/format.ts
+++ b/common/util/format.ts
@@ -19,7 +19,9 @@ export function formatWithCommas(amount: number) {
 }
 
 export function formatPercent(zeroToOne: number) {
-  return Math.round(zeroToOne * 100) + '%'
+  // Show 1 decimal place if <2% or >99%
+  const decimalPlaces = zeroToOne < 0.02 || zeroToOne > 0.99 ? 1 : 0
+  return (zeroToOne * 100).toFixed(decimalPlaces) + '%'
 }
 
 export function toCamelCase(words: string) {
diff --git a/web/lib/firebase/contracts.ts b/web/lib/firebase/contracts.ts
index 24133c65..5436a25b 100644
--- a/web/lib/firebase/contracts.ts
+++ b/web/lib/firebase/contracts.ts
@@ -21,7 +21,7 @@ import { Binary, Contract, FullContract } from '../../../common/contract'
 import { getDpmProbability } from '../../../common/calculate-dpm'
 import { createRNG, shuffle } from '../../../common/util/random'
 import { getCpmmProbability } from '../../../common/calculate-cpmm'
-import { formatMoney } from '../../../common/util/format'
+import { formatMoney, formatPercent } from '../../../common/util/format'
 import { getCpmmLiquidity } from '../../../common/calculate-cpmm'
 export type { Contract }
 
@@ -58,8 +58,7 @@ export function getBinaryProbPercent(contract: FullContract<any, Binary>) {
       ? getCpmmProbability(pool, p)
       : getDpmProbability(totalShares)
 
-  const probPercent = Math.round(prob * 100) + '%'
-  return probPercent
+  return formatPercent(prob)
 }
 
 export function tradingAllowed(contract: Contract) {