How do I know what size garage door spring I need?
Four measurements determine torsion spring size: wire diameter, inside diameter, overall length, and wind direction, all matched to your door's weight and height. Measure 20 coils to the sixteenth of an inch and divide by 20 for wire size. The catch: if the old spring was mis-sized, copying it repeats the mistake.
The four numbers that define a torsion spring
- Wire diameter. The thickness of the steel itself, usually between .207 and .273 inches on residential doors. This is the number people get wrong most often, because .234 and .243 wire look identical to the eye.
- Inside diameter (ID). Residential springs are almost always 1-3/4 inch or 2 inch ID. It is often stamped on the winding cone, like P175 or 200.
- Overall length. Measured with the spring unwound. A broken spring must be measured in both pieces, then added together.
- Wind direction. Left-wound or right-wound, identified by which way the coil wraps. Put a right-wound spring where a left belongs and the door will not lift.
To get wire diameter without calipers, measure 20 coils tight together and divide by 20. If 20 coils measure 4-5/8 inches, the wire is .231. A ruler marked in sixteenths is accurate enough because manufacturers publish 20-coil reference charts.
Why door weight matters more than the old spring
A spring is really a stored-energy calculation: the door's weight times the drum radius tells you the torque needed, and the spring's dimensions determine how much torque it delivers per turn. A 16x7 non-insulated steel door around NW OKC might weigh 140 to 160 pounds, while the same size door with vinyl-backed insulation runs 180 to 220, and a wood carriage-style door in Nichols Hills can top 350. Those are three different spring setups on doors that look the same from the street.
This is why we weigh or calculate the door instead of blindly matching the old spring. Roughly one in five broken springs we pull off OKC doors was the wrong size to begin with, which is often exactly why it broke early.
Common OKC residential pairings
| Door | Typical weight | Typical setup |
|---|---|---|
| 8x7 single, steel | 75 to 100 lb | One spring, .207 to .218 wire |
| 16x7 double, non-insulated | 140 to 160 lb | Two springs, .225 to .234 wire |
| 16x7 double, insulated | 180 to 230 lb | Two springs, .243 to .250 wire |
| 16x8 carriage / overlay | 250 to 350+ lb | Two heavy springs, sized case by case |
Treat that table as orientation, not a shopping list. Drum size, track radius, and cycle rating all shift the final spec, and a spring that is close but not right leaves the door heavy at the floor or slamming shut from waist height.
The honest cost comparison
Ordering springs online saves only the labor, and against that you are trading a week of shipping, the risk of buying the wrong spec, and the most dangerous DIY job on a house. Professional spring replacement in the OKC metro is priced off what the job actually involves: one spring or a pair, wire size and cycle rating, and whether cables or bearings are due at the same time. The springs come sized off the actual door, balanced, and warrantied, usually same day. If the door is beyond saving, compare against a new door install before sinking money into heavy springs for a failing door. Estimates are free either way.
Let Us Match Your Spring Exactly
Talk to a real OKC technician — 24/7, no after-hours surcharge, free estimates.
Related Questions
Why did my garage door spring break so soon after being replaced?+
Premature failure usually means the spring was undersized for the door, made from low-grade wire, or asked to work alone on a door that needed a pair. Cold snaps and rust accelerate the process but rarely cause it alone. Read the full answer →
What's the difference between oil-tempered and galvanized garage door springs?+
Oil-tempered wire is heat-treated and holds its set tension for the spring's whole life, at the cost of a dark, oily look. Galvanized wire resists corrosion and looks clean but gradually loses tension and needs re-adjustment. For Oklahoma garages, oil-tempered is usually the better buy. Read the full answer →
How many turns does a garage door torsion spring need?+
A common baseline is roughly one full turn per foot of door height plus about a half turn, so a 7-foot door lands near 7.5 turns (30 quarter turns) with standard 4-inch drums. The exact count depends on drum circumference and final balance testing. Read the full answer →
Send it to a neighbor, or save it for later.
Follow Affordable Door Co on Facebook for seasonal garage door tips and local project photos. Still stuck? Contact us.
Related answers
More answers in this category are on the way — browse the full Answer Hub.