diff --git a/internal/services/nginx/nginx_deployment_resource.go b/internal/services/nginx/nginx_deployment_resource.go
index f907214c020d..5e22fb20fb04 100644
--- a/internal/services/nginx/nginx_deployment_resource.go
+++ b/internal/services/nginx/nginx_deployment_resource.go
@@ -100,6 +100,7 @@ func (m DeploymentResource) Arguments() map[string]*pluginsdk.Schema {
 		"capacity": {
 			Type:         pluginsdk.TypeInt,
 			Optional:     true,
+			Default:      20,
 			ValidateFunc: validation.IntPositive,
 		},
 
diff --git a/website/docs/r/nginx_deployment.html.markdown b/website/docs/r/nginx_deployment.html.markdown
index 2c8ce3c474c6..bfaf425fda51 100644
--- a/website/docs/r/nginx_deployment.html.markdown
+++ b/website/docs/r/nginx_deployment.html.markdown
@@ -91,7 +91,7 @@ The following arguments are supported:
 
 ---
 
-* `capacity` - (Optional) Specify the number of NGINX capacity units for this NGINX deployment.
+* `capacity` - (Optional) Specify the number of NGINX capacity units for this NGINX deployment. Defaults to `20`.
 
 -> **Note** For more information on NGINX capacity units, please refer to the [NGINX scaling guidance documentation](https://docs.nginx.com/nginxaas/azure/quickstart/scaling/)