diff --git a/js/test_cases/helpers_size/README.md b/js/test_cases/helpers_size/README.md
new file mode 100644
index 0000000..76b797a
--- /dev/null
+++ b/js/test_cases/helpers_size/README.md
@@ -0,0 +1,18 @@
+Excerpt from [the DustJS tutorial](https://github.com/linkedin/dustjs/wiki/Dust-Tutorial#size_keyxxx___size_helper_Available_in_Dust_V11_release):
+
+    Array - number of elements, [1,2,3,4] has size=4
+    String - length of the string, "abcdef" has size=6
+    Object - Number of properties in the object, {a:4, b:8, c:15, d:16} has size=4
+    Number - Value of the number, 23 has size 23 and 3.14 has size 3.14
+    Undefined, 0, empty string - zero
+    Any other value - length after conversion to string
+
+This appears to be inaccurate (probably out of date because that tutorial was deprecated in favor of [dustjs.com](https://www.dustjs.com/), but the latter is incomplete and lacking any reference to the `@size` helper.
+
+Corrections
+-----------
+- Booleans are 0, not converted to strings
+
+Oddities
+--------
+Reference parameters (like `foo="{bar}"`) are usually treated as strings but it seems if it contains ONLY a reference to a value and not anything else, then it is still treated as a number.
diff --git a/js/test_cases/helpers_size/inputarray.json b/js/test_cases/helpers_size/inputarray.json
new file mode 100644
index 0000000..98f6406
--- /dev/null
+++ b/js/test_cases/helpers_size/inputarray.json
@@ -0,0 +1,7 @@
+{
+  "val": [
+    "Alice",
+    "Bob",
+    "Chris"
+  ]
+}
diff --git a/js/test_cases/helpers_size/inputemptystring.json b/js/test_cases/helpers_size/inputemptystring.json
new file mode 100644
index 0000000..f911fb5
--- /dev/null
+++ b/js/test_cases/helpers_size/inputemptystring.json
@@ -0,0 +1,3 @@
+{
+  "val": ""
+}
diff --git a/js/test_cases/helpers_size/inputfalse.json b/js/test_cases/helpers_size/inputfalse.json
new file mode 100644
index 0000000..9cc7fda
--- /dev/null
+++ b/js/test_cases/helpers_size/inputfalse.json
@@ -0,0 +1,3 @@
+{
+  "val": false
+}
diff --git a/js/test_cases/helpers_size/inputmissing.json b/js/test_cases/helpers_size/inputmissing.json
new file mode 100644
index 0000000..95cf907
--- /dev/null
+++ b/js/test_cases/helpers_size/inputmissing.json
@@ -0,0 +1,3 @@
+{
+  "notval": "Alice"
+}
diff --git a/js/test_cases/helpers_size/inputnumber.json b/js/test_cases/helpers_size/inputnumber.json
new file mode 100644
index 0000000..378b4a9
--- /dev/null
+++ b/js/test_cases/helpers_size/inputnumber.json
@@ -0,0 +1,3 @@
+{
+  "val": 7.21
+}
diff --git a/js/test_cases/helpers_size/inputobject.json b/js/test_cases/helpers_size/inputobject.json
new file mode 100644
index 0000000..e511117
--- /dev/null
+++ b/js/test_cases/helpers_size/inputobject.json
@@ -0,0 +1,6 @@
+{
+  "val": {
+    "name": "fluffy",
+    "pet": "cat"
+  }
+}
diff --git a/js/test_cases/helpers_size/inputstring.json b/js/test_cases/helpers_size/inputstring.json
new file mode 100644
index 0000000..fea025d
--- /dev/null
+++ b/js/test_cases/helpers_size/inputstring.json
@@ -0,0 +1,3 @@
+{
+  "val": "7.99"
+}
diff --git a/js/test_cases/helpers_size/inputtrue.json b/js/test_cases/helpers_size/inputtrue.json
new file mode 100644
index 0000000..25d6b1f
--- /dev/null
+++ b/js/test_cases/helpers_size/inputtrue.json
@@ -0,0 +1,3 @@
+{
+  "val": true
+}
diff --git a/js/test_cases/helpers_size/inputzero.json b/js/test_cases/helpers_size/inputzero.json
new file mode 100644
index 0000000..d6110e8
--- /dev/null
+++ b/js/test_cases/helpers_size/inputzero.json
@@ -0,0 +1,3 @@
+{
+  "val": 0
+}
diff --git a/js/test_cases/helpers_size/main.dust b/js/test_cases/helpers_size/main.dust
new file mode 100644
index 0000000..52b398c
--- /dev/null
+++ b/js/test_cases/helpers_size/main.dust
@@ -0,0 +1,10 @@
+The size of val ({val|js|s}) is {@size key=val /}{~n}
+The size of "{~lb}val{~rb}" is {@size key="{val}" /}{~n}
+{#val foo="{val}"}
+    The size of foo ({foo|js|s}) is {@size key=foo /}{~n}
+    The size of "{~lb}foo{~rb}" is {@size key="{foo}" /}{~n}
+{:else}
+    The size of foo ({foo|js|s}) is {@size key=foo /}{~n}
+    The size of "{~lb}foo{~rb}" is {@size key="{foo}" /}{~n}
+{/val}
+The size with no key is {@size /}{~n}
diff --git a/src/bin.rs b/src/bin.rs
index 3c4c8c2..d5e89d8 100644
--- a/src/bin.rs
+++ b/src/bin.rs
@@ -15,6 +15,7 @@ use renderer::Loopable;
 use renderer::MathNumber;
 use renderer::RenderError;
 use renderer::Renderable;
+use renderer::Sizable;
 use renderer::Truthiness;
 use renderer::WalkError;
 use renderer::Walkable;
@@ -313,6 +314,29 @@ impl Loopable for serde_json::Value {
     }
 }
 
+impl Sizable for serde_json::Value {
+    fn get_size<'a>(&'a self) -> Option<IceResult<'a>> {
+        match self {
+            serde_json::Value::Null => {
+                Some(IceResult::from_owned(OwnedLiteral::LPositiveInteger(0)))
+            }
+            serde_json::Value::Bool(_boolean) => {
+                Some(IceResult::from_owned(OwnedLiteral::LPositiveInteger(0)))
+            }
+            serde_json::Value::Number(_num) => Some(IceResult::from_borrowed(self)),
+            serde_json::Value::String(text) => Some(IceResult::from_owned(
+                OwnedLiteral::LPositiveInteger(text.len().try_into().unwrap()),
+            )),
+            serde_json::Value::Array(arr) => Some(IceResult::from_owned(
+                OwnedLiteral::LPositiveInteger(arr.len().try_into().unwrap()),
+            )),
+            serde_json::Value::Object(obj) => Some(IceResult::from_owned(
+                OwnedLiteral::LPositiveInteger(obj.len().try_into().unwrap()),
+            )),
+        }
+    }
+}
+
 impl Castable for serde_json::Value {
     fn cast_to_type<'a>(&'a self, target: &str) -> Option<IceResult<'a>> {
         match (self, target) {
@@ -329,6 +353,10 @@ impl Castable for serde_json::Value {
                 })
                 .ok(),
             (serde_json::Value::Number(_), "number") => Some(IceResult::from_borrowed(self)),
+            (serde_json::Value::Null, "number") => None,
+            (serde_json::Value::Bool(_), "number") => None,
+            (serde_json::Value::Array(_), "number") => None,
+            (serde_json::Value::Object(_), "number") => None,
             (_, _) => panic!("Unimplemented cast"),
         }
     }
diff --git a/src/parser/parser.rs b/src/parser/parser.rs
index 88e09f2..c25ba08 100644
--- a/src/parser/parser.rs
+++ b/src/parser/parser.rs
@@ -48,6 +48,8 @@ pub enum DustTag<'a> {
     DTHelperAny(ParameterizedBlock<'a>),
     DTHelperNone(ParameterizedBlock<'a>),
     DTHelperMath(ParameterizedBlock<'a>),
+    DTHelperSize(ParameterizedBlock<'a>),
+    DTHelperContextDump(ParameterizedBlock<'a>),
 }
 
 #[derive(Clone, Debug, PartialEq)]
@@ -286,6 +288,14 @@ fn dust_tag_helper(i: &str) -> IResult<&str, DustTag> {
             parameterized_block("{@", &tag_to_path("math")),
             DustTag::DTHelperMath,
         ),
+        map(
+            parameterized_block("{@", &tag_to_path("size")),
+            DustTag::DTHelperSize,
+        ),
+        map(
+            parameterized_block("{@", &tag_to_path("contextDump")),
+            DustTag::DTHelperContextDump,
+        ),
     ))(i)
 }
 
@@ -348,7 +358,10 @@ fn key_to_path<'a>(i: &'a str) -> IResult<&str, Path<'a>> {
 fn postitive_integer_literal(i: &str) -> IResult<&str, u64> {
     map(
         verify(
-            map(digit1, |number_string: &str| number_string.parse::<u64>()),
+            map(
+                recognize(tuple((opt(tag("+")), digit1))),
+                |number_string: &str| number_string.parse::<u64>(),
+            ),
             |parse_result| parse_result.is_ok(),
         ),
         |parsed_number| parsed_number.unwrap(),
@@ -424,7 +437,11 @@ fn key_value_pair(i: &str) -> IResult<&str, KVPair> {
 
 /// Display a value from the context
 fn reference(i: &str) -> IResult<&str, Reference> {
-    let (remaining, (p, filters)) = delimited(tag("{"), tuple((path, many0(filter))), tag("}"))(i)?;
+    let (remaining, (p, filters)) = delimited(
+        tag("{"),
+        tuple((path, many0(filter))),
+        preceded(space0, tag("}")),
+    )(i)?;
     Ok((
         remaining,
         Reference {
@@ -474,12 +491,8 @@ where
                     preceded(tag(open_matcher), name_matcher),
                     opt(preceded(tag(":"), path)),
                     terminated(
-                        opt(delimited(
-                            space1,
-                            separated_list1(space1, key_value_pair),
-                            space0,
-                        )),
-                        tag("}"),
+                        opt(preceded(space1, separated_list1(space1, key_value_pair))),
+                        preceded(space0, tag("}")),
                     ),
                     opt(body),
                     opt(preceded(tag("{:else}"), opt(body))),
@@ -515,12 +528,8 @@ where
                     preceded(tag(open_matcher), name_matcher),
                     opt(preceded(tag(":"), path)),
                     terminated(
-                        opt(delimited(
-                            space1,
-                            separated_list1(space1, key_value_pair),
-                            space0,
-                        )),
-                        tag("}"),
+                        opt(preceded(space1, separated_list1(space1, key_value_pair))),
+                        preceded(space0, tag("}")),
                     ),
                     opt(body),
                     delimited(tag("{/"), name_matcher, tag("}")),
@@ -554,13 +563,9 @@ where
             tuple((
                 name_matcher,
                 opt(preceded(tag(":"), path)),
-                opt(delimited(
-                    space1,
-                    separated_list1(space1, key_value_pair),
-                    space0,
-                )),
+                opt(preceded(space1, separated_list1(space1, key_value_pair))),
             )),
-            tag("/}"),
+            preceded(space0, tag("/}")),
         )(i)?;
 
         Ok((
@@ -585,13 +590,9 @@ fn partial_with_plain_tag<'a>(
             tuple((
                 key,
                 opt(preceded(tag(":"), path)),
-                opt(delimited(
-                    space1,
-                    separated_list1(space1, key_value_pair),
-                    space0,
-                )),
+                opt(preceded(space1, separated_list1(space1, key_value_pair))),
             )),
-            tag("/}"),
+            preceded(space0, tag("/}")),
         )(i)?;
 
         Ok((
@@ -623,13 +624,9 @@ fn partial_with_quoted_tag<'a>(
             tuple((
                 template_string_rvalue,
                 opt(preceded(tag(":"), path)),
-                opt(delimited(
-                    space1,
-                    separated_list1(space1, key_value_pair),
-                    space0,
-                )),
+                opt(preceded(space1, separated_list1(space1, key_value_pair))),
             )),
-            tag("/}"),
+            preceded(space0, tag("/}")),
         )(i)?;
 
         Ok((
diff --git a/src/renderer/context_element.rs b/src/renderer/context_element.rs
index 56d194c..01281d3 100644
--- a/src/renderer/context_element.rs
+++ b/src/renderer/context_element.rs
@@ -22,6 +22,7 @@ pub trait ContextElement:
     + FromContextElement
     + IntoRcIce
     + Castable
+    + Sizable
 {
 }
 
@@ -63,6 +64,10 @@ pub trait Castable {
     fn cast_to_type<'a>(&'a self, target: &str) -> Option<IceResult<'a>>;
 }
 
+pub trait Sizable {
+    fn get_size<'a>(&'a self) -> Option<IceResult<'a>>;
+}
+
 pub trait CastToAny {
     fn to_any(&self) -> &dyn Any;
 }
diff --git a/src/renderer/inline_partial_tree.rs b/src/renderer/inline_partial_tree.rs
index f7cbfdf..fffe0a8 100644
--- a/src/renderer/inline_partial_tree.rs
+++ b/src/renderer/inline_partial_tree.rs
@@ -112,7 +112,9 @@ fn extract_inline_partials_from_tag<'a, 'b>(
         | DustTag::DTHelperSelect(parameterized_block)
         | DustTag::DTHelperAny(parameterized_block)
         | DustTag::DTHelperNone(parameterized_block)
-        | DustTag::DTHelperMath(parameterized_block) => {
+        | DustTag::DTHelperMath(parameterized_block)
+        | DustTag::DTHelperSize(parameterized_block)
+        | DustTag::DTHelperContextDump(parameterized_block) => {
             match &parameterized_block.contents {
                 None => (),
                 Some(body) => extract_inline_partials_from_body(blocks, &body),
diff --git a/src/renderer/mod.rs b/src/renderer/mod.rs
index 571a02b..9b1f5b7 100644
--- a/src/renderer/mod.rs
+++ b/src/renderer/mod.rs
@@ -18,6 +18,7 @@ pub use context_element::IceResult;
 pub use context_element::IntoContextElement;
 pub use context_element::Loopable;
 pub use context_element::Renderable;
+pub use context_element::Sizable;
 pub use context_element::Truthiness;
 pub use context_element::Walkable;
 pub use errors::CompileError;
diff --git a/src/renderer/parameters_context.rs b/src/renderer/parameters_context.rs
index a886586..94a8e13 100644
--- a/src/renderer/parameters_context.rs
+++ b/src/renderer/parameters_context.rs
@@ -1,6 +1,7 @@
 use crate::parser::Filter;
 use crate::parser::KVPair;
 use crate::parser::OwnedLiteral;
+use crate::parser::PartialNameElement;
 use crate::parser::RValue;
 use crate::renderer::breadcrumb_tree::BreadcrumbTreeElement;
 use crate::renderer::context_element::CompareContextElement;
@@ -14,12 +15,14 @@ use crate::renderer::DustRenderer;
 use crate::renderer::Loopable;
 use crate::renderer::RenderError;
 use crate::renderer::Renderable;
+use crate::renderer::Sizable;
 use crate::renderer::Truthiness;
 use crate::renderer::WalkError;
 use crate::renderer::Walkable;
 use std::borrow::Borrow;
 use std::cmp::Ordering;
 use std::collections::HashMap;
+use std::convert::TryInto;
 
 #[derive(Debug)]
 pub struct ParametersContext<'a> {
@@ -189,6 +192,19 @@ impl Walkable for OwnedLiteral {
     }
 }
 
+impl Sizable for OwnedLiteral {
+    fn get_size<'a>(&'a self) -> Option<IceResult<'a>> {
+        match self {
+            OwnedLiteral::LFloat(_) => Some(IceResult::from_borrowed(self)),
+            OwnedLiteral::LPositiveInteger(_) => Some(IceResult::from_borrowed(self)),
+            OwnedLiteral::LNegativeInteger(_) => Some(IceResult::from_borrowed(self)),
+            OwnedLiteral::LString(text) => Some(IceResult::from_owned(
+                OwnedLiteral::LPositiveInteger(text.len().try_into().unwrap()),
+            )),
+        }
+    }
+}
+
 impl Castable for OwnedLiteral {
     fn cast_to_type<'a>(&'a self, target: &str) -> Option<IceResult<'a>> {
         match (self, target) {
diff --git a/src/renderer/renderer.rs b/src/renderer/renderer.rs
index cf48524..561d224 100644
--- a/src/renderer/renderer.rs
+++ b/src/renderer/renderer.rs
@@ -722,6 +722,85 @@ impl<'a> DustRenderer<'a> {
                     }
                 }
             }
+            DustTag::DTHelperSize(parameterized_block) => {
+                let param_map =
+                    ParametersContext::new(self, breadcrumbs, &parameterized_block.params, None);
+                let value = self.tap(breadcrumbs, &param_map, "key");
+                let value_ce = value.as_ref().map(|maybe_ice| {
+                    maybe_ice
+                        .as_ref()
+                        .map(|ice| ice.get_context_element_reference())
+                    // .map(|ce| ce.get_size())
+                });
+                match value_ce {
+                    // If "key" is not on the @size tag at all, render 0.
+                    None => return Ok("0".to_owned()),
+                    // If the key value could not be found in the context, render 0.
+                    Some(Err(_)) => return Ok("0".to_owned()),
+                    Some(Ok(ce)) => {
+                        // The @size helper attempts to cast values to
+                        // numbers, and if that succeeds it uses the
+                        // number, otherwise we'll get the size of the
+                        // original type.
+                        match ce.cast_to_type("number") {
+                            Some(ice) => {
+                                return ice
+                                    .get_context_element_reference()
+                                    .get_size()
+                                    .map(|ce_size| {
+                                        ce_size.get_context_element_reference().render(&Vec::new())
+                                    })
+                                    .unwrap_or(Ok("".to_owned()))
+                            }
+                            None => {
+                                return ce
+                                    .get_size()
+                                    .map(|ce_size| {
+                                        ce_size.get_context_element_reference().render(&Vec::new())
+                                    })
+                                    .unwrap_or(Ok("".to_owned()))
+                            }
+                        }
+                    }
+                }
+            }
+            DustTag::DTHelperContextDump(parameterized_block) => {
+                let param_map =
+                    ParametersContext::new(self, breadcrumbs, &parameterized_block.params, None);
+                let value = self.tap(breadcrumbs, &param_map, "key");
+                let destination = self.tap(breadcrumbs, &param_map, "to");
+                let value_rendered = match value.as_ref().map(|maybe_ice| {
+                    maybe_ice
+                        .as_ref()
+                        .map(|ice| ice.get_context_element_reference())
+                        .map(|ce| ce.render(&Vec::new()))
+                }) {
+                    Some(Ok(Ok(val))) => val,
+                    _ => "current".to_owned(),
+                };
+                let destination_rendered = match destination.as_ref().map(|maybe_ice| {
+                    maybe_ice
+                        .as_ref()
+                        .map(|ice| ice.get_context_element_reference())
+                        .map(|ce| ce.render(&Vec::new()))
+                }) {
+                    Some(Ok(Ok(val))) => val,
+                    _ => "output".to_owned(),
+                };
+                match (
+                    value_rendered.as_str(),
+                    destination_rendered.as_str(),
+                    breadcrumbs.last(),
+                ) {
+                    ("current", "output", None) => return Ok("{}".to_owned()),
+                    ("current", "console", None) => println!("{{}}"),
+                    ("current", "output", Some(bc)) => return Ok(format!("{:?}", bc)),
+                    ("current", "console", Some(bc)) => println!("{:?}", bc),
+                    ("full", "output", _) => return Ok(format!("{:?}", breadcrumbs)),
+                    ("full", "console", _) => println!("{:?}", breadcrumbs),
+                    _ => panic!("Unhandled contextDump parameters."),
+                }
+            }
         }
 
         Ok("".to_owned())