diff --git a/pkg/tsdb/prometheus/time_series_query.go b/pkg/tsdb/prometheus/time_series_query.go
index fbb2497cc8e..2b95756db07 100644
--- a/pkg/tsdb/prometheus/time_series_query.go
+++ b/pkg/tsdb/prometheus/time_series_query.go
@@ -177,17 +177,9 @@ func (s *Service) parseTimeSeriesQuery(queryContext *backend.QueryDataRequest, d
 			interval = time.Duration(int64(adjustedInterval) * intervalFactor)
 		}
 
-		intervalMs := int64(interval / time.Millisecond)
-		rangeS := query.TimeRange.To.Unix() - query.TimeRange.From.Unix()
-
 		// Interpolate variables in expr
-		expr := model.Expr
-		expr = strings.ReplaceAll(expr, varIntervalMs, strconv.FormatInt(intervalMs, 10))
-		expr = strings.ReplaceAll(expr, varInterval, intervalv2.FormatDuration(interval))
-		expr = strings.ReplaceAll(expr, varRangeMs, strconv.FormatInt(rangeS*1000, 10))
-		expr = strings.ReplaceAll(expr, varRangeS, strconv.FormatInt(rangeS, 10))
-		expr = strings.ReplaceAll(expr, varRange, strconv.FormatInt(rangeS, 10)+"s")
-		expr = strings.ReplaceAll(expr, varRateInterval, intervalv2.FormatDuration(calculateRateInterval(interval, dsInfo.TimeInterval, s.intervalCalculator)))
+		timeRange := query.TimeRange.To.Sub(query.TimeRange.From)
+		expr := interpolateVariables(model.Expr, interval, timeRange, s.intervalCalculator, dsInfo.TimeInterval)
 
 		rangeQuery := model.RangeQuery
 		if !model.InstantQuery && !model.RangeQuery {
@@ -262,6 +254,19 @@ func calculateRateInterval(interval time.Duration, scrapeInterval string, interv
 	return rateInterval
 }
 
+func interpolateVariables(expr string, interval time.Duration, timeRange time.Duration, intervalCalculator intervalv2.Calculator, timeInterval string) string {
+	rangeMs := timeRange.Milliseconds()
+	rangeSRounded := int64(math.Round(float64(rangeMs) / 1000.0))
+
+	expr = strings.ReplaceAll(expr, varIntervalMs, strconv.FormatInt(int64(interval/time.Millisecond), 10))
+	expr = strings.ReplaceAll(expr, varInterval, intervalv2.FormatDuration(interval))
+	expr = strings.ReplaceAll(expr, varRangeMs, strconv.FormatInt(rangeMs, 10))
+	expr = strings.ReplaceAll(expr, varRangeS, strconv.FormatInt(rangeSRounded, 10))
+	expr = strings.ReplaceAll(expr, varRange, strconv.FormatInt(rangeSRounded, 10)+"s")
+	expr = strings.ReplaceAll(expr, varRateInterval, intervalv2.FormatDuration(calculateRateInterval(interval, timeInterval, intervalCalculator)))
+	return expr
+}
+
 func matrixToDataFrames(matrix model.Matrix, query *PrometheusQuery, frames data.Frames) data.Frames {
 	for _, v := range matrix {
 		tags := make(map[string]string, len(v.Metric))
diff --git a/pkg/tsdb/prometheus/time_series_query_test.go b/pkg/tsdb/prometheus/time_series_query_test.go
index 30360f7ea17..10992a03841 100644
--- a/pkg/tsdb/prometheus/time_series_query_test.go
+++ b/pkg/tsdb/prometheus/time_series_query_test.go
@@ -281,6 +281,44 @@ func TestPrometheus_timeSeriesQuery_parseTimeSeriesQuery(t *testing.T) {
 		require.Equal(t, "rate(ALERTS{job=\"test\" [172800]})", models[0].Expr)
 	})
 
+	t.Run("parsing query model with $__range_s variable below 0.5s", func(t *testing.T) {
+		timeRange := backend.TimeRange{
+			From: now,
+			To:   now.Add(40 * time.Millisecond),
+		}
+
+		query := queryContext(`{
+			"expr": "rate(ALERTS{job=\"test\" [$__range_s]})",
+			"format": "time_series",
+			"intervalFactor": 1,
+			"refId": "A"
+		}`, timeRange)
+
+		dsInfo := &DatasourceInfo{}
+		models, err := service.parseTimeSeriesQuery(query, dsInfo)
+		require.NoError(t, err)
+		require.Equal(t, "rate(ALERTS{job=\"test\" [0]})", models[0].Expr)
+	})
+
+	t.Run("parsing query model with $__range_s variable between 1-0.5s", func(t *testing.T) {
+		timeRange := backend.TimeRange{
+			From: now,
+			To:   now.Add(800 * time.Millisecond),
+		}
+
+		query := queryContext(`{
+			"expr": "rate(ALERTS{job=\"test\" [$__range_s]})",
+			"format": "time_series",
+			"intervalFactor": 1,
+			"refId": "A"
+		}`, timeRange)
+
+		dsInfo := &DatasourceInfo{}
+		models, err := service.parseTimeSeriesQuery(query, dsInfo)
+		require.NoError(t, err)
+		require.Equal(t, "rate(ALERTS{job=\"test\" [1]})", models[0].Expr)
+	})
+
 	t.Run("parsing query model with $__range_ms variable", func(t *testing.T) {
 		timeRange := backend.TimeRange{
 			From: now,
@@ -300,6 +338,25 @@ func TestPrometheus_timeSeriesQuery_parseTimeSeriesQuery(t *testing.T) {
 		require.Equal(t, "rate(ALERTS{job=\"test\" [172800000]})", models[0].Expr)
 	})
 
+	t.Run("parsing query model with $__range_ms variable below 1s", func(t *testing.T) {
+		timeRange := backend.TimeRange{
+			From: now,
+			To:   now.Add(20 * time.Millisecond),
+		}
+
+		query := queryContext(`{
+			"expr": "rate(ALERTS{job=\"test\" [$__range_ms]})",
+			"format": "time_series",
+			"intervalFactor": 1,
+			"refId": "A"
+		}`, timeRange)
+
+		dsInfo := &DatasourceInfo{}
+		models, err := service.parseTimeSeriesQuery(query, dsInfo)
+		require.NoError(t, err)
+		require.Equal(t, "rate(ALERTS{job=\"test\" [20]})", models[0].Expr)
+	})
+
 	t.Run("parsing query model with $__rate_interval variable", func(t *testing.T) {
 		timeRange := backend.TimeRange{
 			From: now,