diff --git a/cmd/lotus-sim/info.go b/cmd/lotus-sim/info.go
index 67e53b34c..759f2d815 100644
--- a/cmd/lotus-sim/info.go
+++ b/cmd/lotus-sim/info.go
@@ -85,6 +85,7 @@ var infoSimCommand = &cli.Command{
 	Description: "Output information about the simulation.",
 	Subcommands: []*cli.Command{
 		infoCommitGasSimCommand,
+		infoMessageSizeSimCommand,
 		infoWindowPostBandwidthSimCommand,
 		infoCapacityGrowthSimCommand,
 		infoStateGrowthSimCommand,
diff --git a/cmd/lotus-sim/info_message.go b/cmd/lotus-sim/info_message.go
new file mode 100644
index 000000000..b30fadd65
--- /dev/null
+++ b/cmd/lotus-sim/info_message.go
@@ -0,0 +1,91 @@
+package main
+
+import (
+	"fmt"
+	"syscall"
+
+	"github.com/filecoin-project/lotus/chain/stmgr"
+	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/filecoin-project/lotus/cmd/lotus-sim/simulation"
+	"github.com/filecoin-project/lotus/lib/stati"
+	"github.com/ipfs/go-cid"
+	"github.com/streadway/quantile"
+	"github.com/urfave/cli/v2"
+)
+
+var infoMessageSizeSimCommand = &cli.Command{
+	Name:        "message-size",
+	Description: "Output information about message size distribution",
+	Flags: []cli.Flag{
+		&cli.Int64Flag{
+			Name:  "lookback",
+			Value: 0,
+		},
+	},
+	Action: func(cctx *cli.Context) error {
+		node, err := open(cctx)
+		if err != nil {
+			return err
+		}
+		defer node.Close()
+
+		go profileOnSignal(cctx, syscall.SIGUSR2)
+
+		sim, err := node.LoadSim(cctx.Context, cctx.String("simulation"))
+		if err != nil {
+			return err
+		}
+
+		qpoints := []struct{ q, tol float64 }{
+			{0.30, 0.01},
+			{0.40, 0.01},
+			{0.60, 0.01},
+			{0.70, 0.01},
+			{0.80, 0.01},
+			{0.85, 0.01},
+			{0.90, 0.01},
+			{0.95, 0.001},
+			{0.99, 0.0005},
+			{0.999, 0.0001},
+		}
+		estims := make([]quantile.Estimate, len(qpoints))
+		for i, p := range qpoints {
+			estims[i] = quantile.Known(p.q, p.tol)
+		}
+		qua := quantile.New(estims...)
+		hist, err := stati.NewHistogram([]float64{
+			1 << 8, 1 << 10, 1 << 11, 1 << 12, 1 << 13, 1 << 14, 1 << 15, 1 << 16,
+		})
+		if err != nil {
+			return err
+		}
+
+		err = sim.Walk(cctx.Context, cctx.Int64("lookback"), func(
+			sm *stmgr.StateManager, ts *types.TipSet, stCid cid.Cid,
+			messages []*simulation.AppliedMessage,
+		) error {
+			for _, m := range messages {
+				msgSize := float64(m.ChainLength())
+				qua.Add(msgSize)
+				hist.Observe(msgSize)
+			}
+
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+		fmt.Println("Quantiles of message sizes:")
+		for _, p := range qpoints {
+			fmt.Printf("%.1f%%\t%.0f\n", p.q*100, qua.Get(p.q))
+		}
+		fmt.Println()
+		fmt.Println("Histogram of message sizes:")
+		fmt.Printf("Total\t%d\n", hist.Total())
+		for i, b := range hist.Buckets[1:] {
+			fmt.Printf("%.0f\t%d\t%.1f%%\n", b, hist.Get(i), 100*hist.GetRatio(i))
+		}
+
+		return nil
+	},
+}