diff --git a/src/Shape.jl b/src/Shape.jl
index ad0c89c..1ede4af 100644
--- a/src/Shape.jl
+++ b/src/Shape.jl
@@ -18,15 +18,9 @@ function project_back_from_unit_circle(θ::T, half_box_len::Float64) where {T<:R
     return restrict_coordinate(x, half_box_len)
 end
 
-function center_of_mass(particles::Vector{Particle}, half_box_len::Float64)
-    x_proj_sum = SVector(0.0, 0.0)
-    y_proj_sum = SVector(0.0, 0.0)
-
-    for p in particles
-        x_proj_sum += project_to_unit_circle(p.c[1], half_box_len)
-        y_proj_sum += project_to_unit_circle(p.c[2], half_box_len)
-    end
-
+function center_of_mass_from_proj_sums(
+    x_proj_sum::SVector{2,Float64}, y_proj_sum::SVector{2,Float64}, half_box_len::Float64
+)
     # Prevent for example atan(1e-16, 1e-15) != 0 with rounding
     digits = 5
 
@@ -50,6 +44,30 @@ function center_of_mass(particles::Vector{Particle}, half_box_len::Float64)
     return SVector(COM_x, COM_y)
 end
 
+function center_of_mass(centers::AbstractVector{SVector{2,Float64}}, half_box_len::Float64)
+    x_proj_sum = SVector(0.0, 0.0)
+    y_proj_sum = SVector(0.0, 0.0)
+
+    for c in centers
+        x_proj_sum += project_to_unit_circle(c[1], half_box_len)
+        y_proj_sum += project_to_unit_circle(c[2], half_box_len)
+    end
+
+    return center_of_mass_from_proj_sums(x_proj_sum, y_proj_sum, half_box_len)
+end
+
+function center_of_mass(particles::Vector{Particle}, half_box_len::Float64)
+    x_proj_sum = SVector(0.0, 0.0)
+    y_proj_sum = SVector(0.0, 0.0)
+
+    for p in particles
+        x_proj_sum += project_to_unit_circle(p.c[1], half_box_len)
+        y_proj_sum += project_to_unit_circle(p.c[2], half_box_len)
+    end
+
+    return center_of_mass_from_proj_sums(x_proj_sum, y_proj_sum, half_box_len)
+end
+
 function gyration_tensor(particles::Vector{Particle}, half_box_len::Float64)
     COM = center_of_mass(particles, half_box_len)