diff --git a/README.md b/README.md
index 79ab596..d6a8b18 100644
--- a/README.md
+++ b/README.md
@@ -37,12 +37,20 @@ remove  5%
 update 10%
 ```
 
+### Custom
+
+Define your own workload pattern with flexible operation percentages.
+
 ## How to run it?
 
 ```sh
 mv results results.bk
-./scripts/bench.bash
-./scripts/plot.bash
+
+./scripts/bench.bash # benchmark all
+# ./scripts/bench.bash -w Custom -h std --read 60 --insert 20 --remove 20 --skip CHashMap
+
+./scripts/plot.bash # plot all
+# ./scripts/plot.bash -f ReadHeavy.std,Custom.std
 ```
 
 ## Results
diff --git a/scripts/bench.bash b/scripts/bench.bash
index dbd5b8a..d34545e 100755
--- a/scripts/bench.bash
+++ b/scripts/bench.bash
@@ -1,36 +1,60 @@
 #!/usr/bin/env bash
 
-set -x
-
 BIN=./target/release/conc-map-bench
 OUT=./results
 
+WORKLOADS=("ReadHeavy" "Exchange" "RapidGrow")
+HASHERS=("std" "ahash")
+
+EXTRA_ARGS=()
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        -w|--workload)
+            if [[ "$2" == "Custom" ]]; then
+                WORKLOADS=("Custom")
+            else
+                IFS=',' read -ra WORKLOADS <<< "$2"
+            fi
+            shift 2
+            ;;
+        -h|--hasher)
+            IFS=',' read -ra HASHERS <<< "$2"
+            shift 2
+            ;;
+        *)
+            # Pass all other arguments through
+            EXTRA_ARGS+=("$1")
+            shift
+            ;;
+    esac
+done
+
+set -x
+
 cargo build --release
 mkdir -p "$OUT"
 
 function bench {
-    ARGS=$3
+    local workload="$1"
+    local hasher="$2"
+    
     date
 
-    file="$OUT/$1.$2.csv"
+    file="$OUT/$workload.$hasher.csv"
 
     if [ -s "$file" ]; then
-        ARGS+=" --csv-no-headers"
+        EXTRA_ARGS+=("--csv-no-headers")
     fi
 
-    skip=$(cat "$file" | cut -d, -f1 | uniq | paste -sd ' ' -)
-
-    if ! "$BIN" bench -w $1 -h $2 $ARGS --skip $skip --csv 2>>"$file"; then
-        bench "$1" "$2" "$3"
+    if ! "$BIN" bench -w "$workload" -h "$hasher" "${EXTRA_ARGS[@]}" --csv 2>>"$file"; then
+        bench "$workload" "$hasher"
     fi
 }
 
-bench ReadHeavy std
-bench Exchange std
-bench RapidGrow std
-
-bench ReadHeavy ahash
-bench Exchange ahash
-bench RapidGrow ahash
+for workload in "${WORKLOADS[@]}"; do
+    for hasher in "${HASHERS[@]}"; do
+        bench "$workload" "$hasher"
+    done
+done
 
 date
diff --git a/scripts/plot.bash b/scripts/plot.bash
index 4e39cc8..9d20f8f 100755
--- a/scripts/plot.bash
+++ b/scripts/plot.bash
@@ -1,19 +1,34 @@
 #!/usr/bin/env bash
 
-set -e
-
 BIN=./target/release/conc-map-bench
 DATA_DIR=results
 
+DATA_FILES=("ReadHeavy.std" "Exchange.std" "RapidGrow.std" "ReadHeavy.ahash" "Exchange.ahash" "RapidGrow.ahash")
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        -f|--files)
+            IFS=',' read -ra DATA_FILES <<< "$2"
+            shift 2
+            ;;
+    esac
+done
+
+set -x
+
 cargo build --release
 
 function plot {
-    cat "$DATA_DIR/$1.csv" | "$BIN" plot "$DATA_DIR" "$1"
+    local data_file="$1"
+    
+    if [ ! -f "$DATA_DIR/$data_file.csv" ]; then
+        echo "Warning: $DATA_DIR/$data_file.csv not found, skipping..."
+        return
+    fi
+    
+    cat "$DATA_DIR/$data_file.csv" | "$BIN" plot "$DATA_DIR" "$data_file"
 }
 
-plot ReadHeavy.std
-plot Exchange.std
-plot RapidGrow.std
-plot ReadHeavy.ahash
-plot Exchange.ahash
-plot RapidGrow.ahash
+for data_file in "${DATA_FILES[@]}"; do
+    plot "$data_file"
+done
\ No newline at end of file
diff --git a/src/bench.rs b/src/bench.rs
index 7f7541e..c7cc3e6 100644
--- a/src/bench.rs
+++ b/src/bench.rs
@@ -40,6 +40,22 @@ pub struct Options {
     pub csv: bool,
     #[structopt(long)]
     pub csv_no_headers: bool,
+
+    // Custom workload parameters
+    #[structopt(long, help = "Read percentage (0-100)")]
+    pub read: Option<u8>,
+    #[structopt(long, help = "Insert percentage (0-100)")]
+    pub insert: Option<u8>,
+    #[structopt(long, help = "Remove percentage (0-100)")]
+    pub remove: Option<u8>,
+    #[structopt(long, help = "Update percentage (0-100)")]
+    pub update: Option<u8>,
+    #[structopt(long, help = "Upsert percentage (0-100)")]
+    pub upsert: Option<u8>,
+    #[structopt(long, help = "Initial capacity log2", default_value = "25")]
+    pub capacity_log2: u8,
+    #[structopt(long, help = "Prefill fraction (0.0-1.0)", default_value = "0.75")]
+    pub prefill: f64,
 }
 
 fn gc_cycle(options: &Options) {
@@ -51,6 +67,27 @@ fn gc_cycle(options: &Options) {
     }
 }
 
+fn validate_workload(options: &Options) -> Result<(), &str> {
+    if matches!(options.workload, workloads::WorkloadKind::Custom) {
+        let read = options.read.unwrap_or(0);
+        let insert = options.insert.unwrap_or(0);
+        let remove = options.remove.unwrap_or(0);
+        let update = options.update.unwrap_or(0);
+        let upsert = options.upsert.unwrap_or(0);
+        let prefill = options.prefill;
+
+        let total = read + insert + remove + update + upsert;
+
+        if total != 100 {
+            return Err("operations percentages must sum to 100");
+        }
+        if prefill < 0.0 || prefill > 1.0 {
+            return Err("prefill must be between 0.0 and 1.0");
+        }
+    }
+    Ok(())
+}
+
 type Handler = Box<dyn FnMut(&str, u32, &Measurement)>;
 
 fn case<C>(name: &str, options: &Options, handler: &mut Handler)
@@ -124,6 +161,12 @@ where
 }
 
 pub fn bench(options: &Options) {
+    // Process custom workload options, if parameters are provided
+    if let Err(e) = validate_workload(options) {
+        eprintln!("Error validating custom workload: {}", e);
+        std::process::exit(1);
+    }
+
     println!("== {:?}", options.workload);
 
     let mut handler = if options.csv {
diff --git a/src/workloads.rs b/src/workloads.rs
index cd724e7..cce3f93 100644
--- a/src/workloads.rs
+++ b/src/workloads.rs
@@ -9,6 +9,7 @@ pub enum WorkloadKind {
     ReadHeavy,
     Exchange,
     RapidGrow,
+    Custom,
 }
 
 impl FromStr for WorkloadKind {
@@ -19,6 +20,7 @@ impl FromStr for WorkloadKind {
             "ReadHeavy" => Ok(Self::ReadHeavy),
             "Exchange" => Ok(Self::Exchange),
             "RapidGrow" => Ok(Self::RapidGrow),
+            "Custom" => Ok(Self::Custom),
             _ => Err("unknown workload"),
         }
     }
@@ -66,11 +68,27 @@ fn exchange(threads: u32) -> Workload {
         .prefill_fraction(0.75)
 }
 
+fn custom(options: &Options, threads: u32) -> Workload {
+    // already checked the percentages sum to 100
+    let mix = Mix {
+        read: options.read.unwrap_or(0),
+        insert: options.insert.unwrap_or(0),
+        remove: options.remove.unwrap_or(0),
+        update: options.update.unwrap_or(0),
+        upsert: options.upsert.unwrap_or(0),
+    };
+
+    *Workload::new(threads as usize, mix)
+        .initial_capacity_log2(options.capacity_log2)
+        .prefill_fraction(options.prefill)
+}
+
 pub(crate) fn create(options: &Options, threads: u32) -> Workload {
     let mut workload = match options.workload {
         WorkloadKind::ReadHeavy => read_heavy(threads),
         WorkloadKind::Exchange => exchange(threads),
         WorkloadKind::RapidGrow => rapid_grow(threads),
+        WorkloadKind::Custom => custom(options, threads),
     };
 
     workload.operations(options.operations);