diff --git a/ViewBest.tsx b/ViewBest.tsx
index cf59513..b76b59b 100644
--- a/ViewBest.tsx
+++ b/ViewBest.tsx
@@ -11,7 +11,7 @@ import {FileSystem} from 'react-native-file-access';
 import {IconButton} from 'react-native-paper';
 import Share from 'react-native-share';
 import {captureScreen} from 'react-native-view-shot';
-import {getVolumes, getWeightsBy} from './best.service';
+import {getOneRepMax, getVolumes, getWeightsBy} from './best.service';
 import {BestPageParams} from './BestPage';
 import Chart from './Chart';
 import {PADDING} from './constants';
@@ -59,12 +59,18 @@ export default function ViewBest() {
   );
 
   useEffect(() => {
-    if (metric === Metrics.Weight)
-      getWeightsBy(params.best.name, period).then(setWeights);
-    else if (metric === Metrics.Volume)
-      getVolumes(params.best.name, period).then(setVolumes);
     console.log(`${ViewBest.name}.useEffect`, {metric});
     console.log(`${ViewBest.name}.useEffect`, {period});
+    switch (metric) {
+      case Metrics.Weight:
+        getWeightsBy(params.best.name, period).then(setWeights);
+        break;
+      case Metrics.Volume:
+        getVolumes(params.best.name, period).then(setVolumes);
+        break;
+      default:
+        getOneRepMax({name: params.best.name, period}).then(setWeights);
+    }
   }, [params.best.name, metric, period]);
 
   return (
@@ -76,6 +82,7 @@ export default function ViewBest() {
         onValueChange={value => setMetric(value)}>
         <Picker.Item value={Metrics.Volume} label={Metrics.Volume} />
         <Picker.Item value={Metrics.Weight} label={Metrics.Weight} />
+        <Picker.Item value={Metrics.OneRepMax} label={Metrics.OneRepMax} />
       </Picker>
       <Picker
         style={{color: dark ? 'white' : 'black'}}
@@ -86,7 +93,7 @@ export default function ViewBest() {
         <Picker.Item value={Periods.Monthly} label={Periods.Monthly} />
         <Picker.Item value={Periods.Yearly} label={Periods.Yearly} />
       </Picker>
-      {metric === Metrics.Volume && (
+      {metric === Metrics.Volume ? (
         <Chart
           yData={volumes.map(v => v.value)}
           yFormat={(value: number) =>
@@ -97,8 +104,7 @@ export default function ViewBest() {
           xData={weights}
           xFormat={(_value, index) => formatMonth(weights[index].created!)}
         />
-      )}
-      {metric === Metrics.Weight && (
+      ) : (
         <Chart
           yData={weights.map(set => set.weight)}
           yFormat={value => `${value}${weights[0].unit}`}
diff --git a/best.service.ts b/best.service.ts
index 43eee49..8ff71af 100644
--- a/best.service.ts
+++ b/best.service.ts
@@ -4,6 +4,31 @@ import Set from './set';
 import {defaultSet} from './set.service';
 import Volume from './volume';
 
+export const getOneRepMax = async ({
+  name,
+  period,
+}: {
+  name: string;
+  period: Periods;
+}) => {
+  // Brzycki formula https://en.wikipedia.org/wiki/One-repetition_maximum#Brzycki
+  const select = `
+    SELECT max(weight / (1.0278 - 0.0278 * reps)) AS weight, 
+    STRFTIME('%Y-%m-%d', created) as created, unit
+    FROM sets
+    WHERE name = ? AND NOT hidden
+    AND DATE(created) >= DATE('now', 'weekday 0', ?)
+    GROUP BY name, STRFTIME(?, created)
+  `;
+  let difference = '-7 days';
+  if (period === Periods.Monthly) difference = '-1 months';
+  else if (period === Periods.Yearly) difference = '-1 years';
+  let group = '%Y-%m-%d';
+  if (period === Periods.Yearly) group = '%Y-%m';
+  const [result] = await db.executeSql(select, [name, difference, group]);
+  return result.rows.raw();
+};
+
 export const getBestSet = async (name: string): Promise<Set> => {
   const bestWeight = `
     SELECT name, reps, unit, MAX(weight) AS weight 
diff --git a/metrics.ts b/metrics.ts
index 0c2998b..cebda6f 100644
--- a/metrics.ts
+++ b/metrics.ts
@@ -1,4 +1,5 @@
 export enum Metrics {
   Weight = 'Best weight per day',
   Volume = 'Volume per day',
+  OneRepMax = 'One rep max',
 }