diff --git a/app/controllers/quantities_controller.rb b/app/controllers/quantities_controller.rb
index 50c573c..5eda6c2 100644
--- a/app/controllers/quantities_controller.rb
+++ b/app/controllers/quantities_controller.rb
@@ -1,4 +1,9 @@
 class QuantitiesController < ApplicationController
+  before_action only: :new do
+    find_quantity if params[:id].present?
+  end
+  before_action :find_quantity, only: [:edit, :update, :rebase, :destroy]
+
   before_action except: :index do
     raise AccessForbidden unless current_user.at_least(:active)
   end
@@ -6,4 +11,34 @@ class QuantitiesController < ApplicationController
   def index
     @quantities = current_user.quantities.includes(:parent).includes(:subquantities).ordered
   end
+
+  def new
+    @quantity = current_user.quantities.new(parent: @quantity)
+  end
+
+  def create
+    @quantity = current_user.quantities.new(quantity_params)
+    if @quantity.save
+      @before, @quantity, @ancestors = @quantity.succ_and_ancestors
+      flash.now[:notice] = t('.success', quantity: @quantity)
+    else
+      render :new
+    end
+  end
+
+  def destroy
+    @quantity.destroy!
+    @ancestors = @quantity.ancestors
+    flash.now[:notice] = t('.success', quantity: @quantity)
+  end
+
+  private
+
+  def quantity_params
+    params.require(:quantity).permit(Quantity::ATTRIBUTES)
+  end
+
+  def find_quantity
+    @quantity = Quantity.find_by!(id: params[:id], user: current_user)
+  end
 end
diff --git a/app/models/quantity.rb b/app/models/quantity.rb
index d62b815..89c47b5 100644
--- a/app/models/quantity.rb
+++ b/app/models/quantity.rb
@@ -1,4 +1,6 @@
 class Quantity < ApplicationRecord
+  ATTRIBUTES = [:name, :description, :parent_id]
+
   belongs_to :user, optional: true
   belongs_to :parent, optional: true, class_name: "Quantity"
   has_many :subquantities, class_name: "Quantity", inverse_of: :parent,
@@ -38,7 +40,7 @@ class Quantity < ApplicationRecord
           Arel::Nodes::NamedFunction.new('ROW_NUMBER', [])
             .over(Arel::Nodes::Window.new.partition(parent_column).order(order_column)),
           Arel::SelectManager.new.project(
-            Arel::Nodes::NamedFunction.new('LENGTH', [Arel.star.count])])
+            Arel::Nodes::NamedFunction.new('LENGTH', [Arel.star.count])
           ),
           Arel::Nodes.build_quoted('0')
         ],
@@ -51,30 +53,54 @@ class Quantity < ApplicationRecord
   end
 
   def movable?
-    subunits.empty?
+    subquantities.empty?
   end
 
   def default?
     parent_id.nil?
   end
 
-  # Return: record, its ancestors and succesive record in order of appearance,
-  # including :depth attribute. Used for table view reload.
-  def successive
+  # Return: self, ancestors and successive record in order of appearance,
+  # including :depth attribute. Used for partial view reload.
+  def succ_and_ancestors
     quantities = Quantity.arel_table
     ancestors = Arel::Table.new('ancestors')
+
     Quantity.with(
       ancestors: user.quantities.ordered.select(
         Arel::Nodes::NamedFunction.new('LAG', [quantities[:id]]).over.as('lag_id')
       )
     )
-    .with_recursive(quantities: [
-      Arel::SelectManager.new.project(ancestors[Arel.star]).from(ancestors)
-        .where(ancestors[:id].eq(id).or(ancestors[:lag_id].eq(id))),
-      Arel::SelectManager.new.project(ancestors[Arel.star]).from(ancestors)
-        .join(quantities).on(quantities[:parent_id].eq(ancestors[:id]))
-        .where(quantities[:lag_id].not_eq(id))
-    ]).order(quantities[:path])
-    # return: .first == self ? nul, ancestors : ancestors.pop, ancestors
+      .with_recursive(quantities: [
+        Arel::SelectManager.new.project(ancestors[Arel.star]).from(ancestors)
+          .where(ancestors[:id].eq(id).or(ancestors[:lag_id].eq(id))),
+        Arel::SelectManager.new.project(ancestors[Arel.star]).from(ancestors)
+          .join(quantities).on(quantities[:parent_id].eq(ancestors[:id]))
+          .where(quantities[:lag_id].not_eq(id))])
+      .order(quantities[:path]).to_a
+      .then do |records|
+        [records.last == self ? nil : records.pop, records.pop, records]
+      end
+  end
+
+  def ancestors
+    quantities = Quantity.arel_table
+    ancestors = Arel::Table.new('ancestors')
+
+    # Ancestors are listed bottom up, so it's impossible to know depth at the
+    # start. Start with depth = 0 and count downwards, then adjust by the
+    # amount needed to set biggest negative depth to 0.
+    Quantity.with_recursive(ancestors: [
+      user.quantities.select(quantities[Arel.star], Arel::Nodes.build_quoted(0).as('depth'))
+        .where(id: parent_id),
+      user.quantities.select(quantities[Arel.star], ancestors[:depth] - 1)
+        .joins(quantities.create_join(
+          ancestors, quantities.create_on(quantities[:id].eq(ancestors[:parent_id]))
+        ))
+    ]).select(ancestors[Arel.star]).from(ancestors).to_a.then do |records|
+      records.map(&:depth).min&.abs.then do |maxdepth|
+        records.each { |r| r.depth += maxdepth }
+      end
+    end
   end
 end
diff --git a/app/views/quantities/_form.html.erb b/app/views/quantities/_form.html.erb
new file mode 100644
index 0000000..a08128a
--- /dev/null
+++ b/app/views/quantities/_form.html.erb
@@ -0,0 +1,19 @@
+<%= tabular_fields_for @quantity, form: form_tag do |form| %>
+  <%- tag.tr id: row, class: "form", onkeydown: "processKey(event)",
+    data: {link: link, form: form_tag, hidden_row: hidden_row} do %>
+
+    <td class="<%= class_names({subquantity: @quantity.parent}) %>">
+      <%= form.text_field :name, required: true, autofocus: true, size: 20 %>
+    </td>
+    <td>
+      <%= form.text_area :description, cols: 30, rows: 1, escape: false %>
+    </td>
+
+    <td class="actions">
+      <%= form.button %>
+      <%= image_link_to t(:cancel), "close-outline", quantities_path, class: 'dangerous',
+        name: :cancel, onclick: render_turbo_stream('form_close', {row: row}) %>
+    </td>
+    <td></td>
+  <% end %>
+<% end %>
diff --git a/app/views/quantities/_form_close.html.erb b/app/views/quantities/_form_close.html.erb
new file mode 100644
index 0000000..e79ea3c
--- /dev/null
+++ b/app/views/quantities/_form_close.html.erb
@@ -0,0 +1,2 @@
+<%= turbo_stream.close_form row %>
+<%= turbo_stream.update :flashes %>
diff --git a/app/views/quantities/_quantity.html.erb b/app/views/quantities/_quantity.html.erb
new file mode 100644
index 0000000..bd6a394
--- /dev/null
+++ b/app/views/quantities/_quantity.html.erb
@@ -0,0 +1,28 @@
+<%= tag.tr id: dom_id(quantity),
+           ondragstart: 'dragStart(event)', ondragend: 'dragEnd(event)',
+           ondragover: 'dragOver(event)', ondrop: 'drop(event)',
+           ondragenter: 'dragEnter(event)', ondragleave: 'dragLeave(event)',
+           data: {drag_path: rebase_quantity_path(quantity),
+                  drop_id: dom_id(quantity.parent || quantity)} do %>
+
+  <td class="link" style="--depth:<%= quantity.depth %>">
+    <%= link_to quantity, edit_quantity_path(quantity), onclick: 'this.blur();',
+      data: {turbo_stream: true} %>
+  </td>
+  <td><%= quantity.description %></td>
+
+  <% if current_user.at_least(:active) %>
+    <td class="actions">
+      <%= image_link_to t('.new_subquantity'), 'plus-outline', new_quantity_path(quantity),
+        id: dom_id(quantity, :new, :link), onclick: 'this.blur();', data: {turbo_stream: true} %>
+
+      <%= image_button_to_if quantity.movable?, t('.destroy'), 'delete-outline',
+        quantity_path(quantity), method: :delete %>
+    </td>
+    <% if quantity.movable? %>
+      <td class="handle" draggable="true">&#x283F</td>
+    <% else %>
+      <td></td>
+    <% end %>
+  <% end %>
+<% end %>
diff --git a/app/views/quantities/create.turbo_stream.erb b/app/views/quantities/create.turbo_stream.erb
new file mode 100644
index 0000000..b73eba5
--- /dev/null
+++ b/app/views/quantities/create.turbo_stream.erb
@@ -0,0 +1,7 @@
+<%= turbo_stream.close_form dom_id(@quantity.parent || Quantity, :new) %>
+<%= turbo_stream.remove :no_items %>
+<% @ancestors.map do |ancestor| %>
+  <%= turbo_stream.replace ancestor %>
+<% end %>
+<%= @before.nil? ? turbo_stream.append(:quantities, @quantity) :
+  turbo_stream.before(@before, @quantity) %>
diff --git a/app/views/quantities/destroy.turbo_stream.erb b/app/views/quantities/destroy.turbo_stream.erb
new file mode 100644
index 0000000..5330055
--- /dev/null
+++ b/app/views/quantities/destroy.turbo_stream.erb
@@ -0,0 +1,5 @@
+<% @ancestors.map do |ancestor| %>
+  <%= turbo_stream.replace ancestor %>
+<% end %>
+<%= turbo_stream.remove @quantity %>
+<%= turbo_stream.append(:quantities, render_no_items) if current_user.quantities.empty? %>
diff --git a/app/views/quantities/new.turbo_stream.erb b/app/views/quantities/new.turbo_stream.erb
new file mode 100644
index 0000000..9ebb8e2
--- /dev/null
+++ b/app/views/quantities/new.turbo_stream.erb
@@ -0,0 +1,20 @@
+<% dom_obj = @quantity.parent || @quantity %>
+<% ids = {row: dom_id(dom_obj, :new),
+          hidden_row: nil,
+          link: dom_id(dom_obj, :new, :link),
+          form_tag: dom_id(dom_obj, :new, :form)} %>
+
+<%= turbo_stream.disable ids[:link] -%>
+
+<%= turbo_stream.append :quantity_form do %>
+  <%- tabular_form_with model: @quantity, html: {id: ids[:form_tag]} do |form| %>
+    <%= form.hidden_field :parent_id unless @quantity.parent.nil? %>
+  <% end %>
+<% end %>
+
+<% if @quantity.parent %>
+  <%= turbo_stream.remove ids[:row] %>
+  <%= turbo_stream.after @quantity.parent, partial: 'form', locals: ids %>
+<% else %>
+  <%= turbo_stream.prepend :quantities, partial: 'form', locals: ids %>
+<% end %>
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 171c407..7527933 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -56,8 +56,15 @@ en:
   quantities:
     navigation: Quantities
     no_items: There are no configured quantities. You can Add some or Import from defaults.
+    quantity:
+      new_subquantity: Child
+      destroy: Delete
     index:
-      new_quantity: New quantity
+      new_quantity: Add quantity
+    create:
+      success: Created new quantity "%{quantity}"
+    destroy:
+      success: Deleted quantity "%{quantity}"
   units:
     navigation: Units
     no_items: There are no configured units. You can Add some or Import from defaults.
@@ -68,8 +75,6 @@ en:
       new_unit: Add unit
       import_units: Import
       top_level_drop: Drop here to reposition into top-level unit
-    new:
-      none: none
     create:
       success: Created new unit "%{unit}"
     update:
diff --git a/config/routes.rb b/config/routes.rb
index 1d13054..5bab666 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,5 +1,7 @@
 Rails.application.routes.draw do
-  resources :quantities
+  resources :quantities, except: [:show], path_names: {new: '(/:id)/new'} do
+    member { post :rebase }
+  end
 
   resources :units, except: [:show], path_names: {new: '(/:id)/new'} do
     member { post :rebase }