Contact Lenses Prescription Conversion Table
Wearing eyeglasses and switching to colored contact lenses? Use this conversion table to translate your frame glasses prescription (SPH) into the equivalent contact lens power. No conversion is needed for prescriptions below -4.00 — the table below only applies to prescriptions of -4.00 and above.
Contact Lenses Prescription Conversion
If you are currently wearing frames and have not yet used contact lenses, we recommend converting your prescription as shown below. Values are rounded down to the nearest available contact lens power.
| -4.00 ~ -7.50 | -7.75 ~ -11.25 | ||
|---|---|---|---|
| Frame Glasses | Contact Lenses | Frame Glasses | Contact Lenses |
| -4.00 | -3.75 | -7.75 | -7.00 |
| -4.25 | -4.00 | -8.00 | -7.25 |
| -4.50 | -4.25 | -8.25 | -7.50 |
| -4.75 | -4.50 | -8.50 | -7.75 |
| -5.00 | -4.75 | -8.75 | -7.75 |
| -5.25 | -5.00 | -9.00 | -8.00 |
| -5.50 | -5.00 | -9.25 | -8.25 |
| -5.75 | -5.25 | -9.50 | -8.50 |
| -6.00 | -5.50 | -9.75 | -8.75 |
| -6.25 | -5.75 | -10.00 | -8.75 |
| -6.50 | -6.00 | -10.25 | -9.00 |
| -6.75 | -6.25 | -10.50 | -9.25 |
| -7.00 | -6.50 | -10.75 | -9.50 |
| -7.25 | -6.50 | -11.00 | -9.75 |
| -7.50 | -6.75 | -11.25 | -9.75 |
How to Use This Table
Find Your Frame Power
Look at the SPH (sphere) value on your glasses prescription and locate it in the Frame Glasses columns above.
Read the Contact Power
Use the matching Contact Lenses value when choosing your power at checkout. Round down if your exact power isn’t listed.
No Power? Choose 0.00
If you have no myopia, select “PLANO” (0.00) for decorative colored contact lenses.
Frequently Asked Questions
Do I need to convert my glasses prescription for contact lenses?
Only for prescriptions of -4.00 or above. Because contact lenses sit directly on your eye, the effective power differs from eyeglasses — the conversion table above gives the correct contact lens power. For prescriptions under -4.00, no conversion is needed.
What does SPH mean on my prescription?
SPH (sphere) is the lens power needed to correct your nearsightedness or farsightedness. A negative SPH (like -4.50) means you are nearsighted (myopic); a positive value means farsighted. You’ll find SPH listed for each eye (OD and OS) on your prescription.
What is Plano (0.00) power?
Plano (0.00) means zero vision correction. If you don’t need your eyesight corrected, choose 0.00 for decorative colored contact lenses — you’ll still need a valid prescription for the lenses.
What if my exact prescription power isn’t in the table?
Choose the closest lower available power. Contact lens powers come in standard increments, and a slightly lower power is always safer and more comfortable than a higher one.
Can I use this table for colored contacts?
Yes — colored contact lenses use the same power system as clear lenses. Use your converted contact lens power when ordering any prescription colored contacts from CCUS.
Does my prescription need to be verified?
Yes. U.S. regulations require a valid prescription for all contact lenses, including zero-power cosmetic lenses. We verify your details before shipping your order — learn more on our prescription verification page.