diff --git a/src/common/utils.spec.ts b/src/common/utils.spec.ts
new file mode 100644
index 000000000..ebd037444
--- /dev/null
+++ b/src/common/utils.spec.ts
@@ -0,0 +1,49 @@
+// Currently only covers converToSI
+import { convertToSI } from './utils';
+import { createUnit, Unit } from 'mathjs';
+
+
+describe('convertToSI', () => {
+  it('should convert a known unit to SI successfully', () => {
+    const result = convertToSI(1, 'cm');
+    expect(result.valueSI).toBeCloseTo(0.01);
+    expect(result.unitSI).toEqual('m');
+  });
+
+  it('should convert angstrom to SI successfully', () => {
+    const result = convertToSI(1, 'Å');
+    expect(result.valueSI).toBeCloseTo(1e-10);
+    expect(result.unitSI).toEqual('m');
+  });
+
+  it('should handle different versions of Å in unicode', () => {
+    const inputUnit = '\u212B'; // Old unicode representation of "Å", is not boolean equal to the one we added.
+    const result = convertToSI(1, inputUnit);
+    expect(result.valueSI).toBeCloseTo(1e-10);
+    expect(result.unitSI).toEqual('m');
+  });
+
+  it('should return the input value and unit if conversion fails', () => {
+    const result = convertToSI(1, 'invalidUnit');
+    expect(result.valueSI).toEqual(1);
+    expect(result.unitSI).toEqual('invalidUnit');
+  });
+
+  it('should convert SI units correctly', () => {
+    const result = convertToSI(1000, 'g');
+    expect(result.valueSI).toBeCloseTo(1);
+    expect(result.unitSI).toEqual('kg');
+  });
+
+  it('should handle already normalized units', () => {
+    const result = convertToSI(1, 'm');
+    expect(result.valueSI).toEqual(1);
+    expect(result.unitSI).toEqual('m');
+  });
+
+  it('should handle negative values properly', () => {
+    const result = convertToSI(-5, 'cm');
+    expect(result.valueSI).toBeCloseTo(-0.05);
+    expect(result.unitSI).toEqual('m');
+  });
+});
\ No newline at end of file
diff --git a/src/common/utils.ts b/src/common/utils.ts
index fcd5f31c3..230def355 100644
--- a/src/common/utils.ts
+++ b/src/common/utils.ts
@@ -25,8 +25,7 @@ export const convertToSI = (
   inputUnit: string,
 ): { valueSI: number; unitSI: string } => {
   try {
-    // catch and normalize the different versions of Å in unicode
-    const normalizedUnit = inputUnit.normalize('NFC');
+    const normalizedUnit = inputUnit.normalize('NFC'); // catch and normalize the different versions of Å in unicode
     // Workaround related to a bug reported at https://github.com/josdejong/mathjs/issues/3097 and https://github.com/josdejong/mathjs/issues/2499
     const quantity = unit(inputValue, normalizedUnit)
       .to(unit(normalizedUnit).toSI().toJSON().unit)