EverTune Calculator
Calculate precise string tension and determine saddle compatibility for your EverTune bridge setup.
Formula: T = (UW * (2 * L * F)^2) / 386.4
329.6 Hz
0.000022
Standard
Tension Curve Across Scale Lengths
Figure 1: Relationship between scale length and tension for the selected gauge and pitch.
| EverTune Module | Tension Range (lbs) | Best For |
|---|---|---|
| Low Tension | 8 – 15 lbs | Thin strings, light touch |
| Standard | 10 – 28 lbs | Most standard guitar sets |
| High Tension | 25 – 45 lbs | Heavy gauges, drop tunings |
Table 1: Official EverTune saddle module tension specifications.
What is an evertune calculator?
An evertune calculator is a specialized technical tool designed for guitarists who use the EverTune constant tension bridge system. Unlike traditional bridges where string tension fluctuates with temperature or humidity, EverTune uses a complex system of springs to maintain a steady pull. However, each saddle has a physical limit. Using an evertune calculator helps you ensure that your chosen string gauge and tuning fall within the operational “Zone 2” of your specific saddle modules.
Who should use it? Professional guitar techs, studio musicians, and enthusiasts who want to switch to drop tunings or custom string sets without hardware failure. A common misconception is that EverTune works with any string at any pitch; in reality, the physics of the string must align with the spring’s counter-force, which is exactly why this evertune calculator is essential.
evertune calculator Formula and Mathematical Explanation
The math behind our evertune calculator is based on the D’Addario string tension formula. The tension (T) is a function of the string’s unit weight, the scale length, and the frequency of the note.
The core equation is: T = (UW × (2 × L × F)²) / 386.4
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| T | Total Tension | Pounds (lbs) | 8 – 45 lbs |
| UW | Unit Weight | lbs/linear inch | 0.00002 – 0.0005 |
| L | Scale Length | Inches (in) | 24.75 – 28 |
| F | Frequency | Hertz (Hz) | 60 – 330 Hz |
Practical Examples (Real-World Use Cases)
Example 1: Standard E on a 25.5″ Scale
If you use a .010 gauge string for your High E (329.63 Hz) on a standard Strat-style guitar, the evertune calculator identifies a tension of approximately 16.2 lbs. This falls perfectly into the Standard EverTune Saddle range. This setup provides a balanced feel and reliable intonation.
Example 2: Drop C Tuning (Low C String)
If you are tuning a .052 gauge string down to C2 (65.41 Hz) on a 25.5″ scale, the tension drops significantly to around 10.5 lbs. Using the evertune calculator, we see this is on the lower edge of the Standard saddle. To maintain better stability, one might choose a .056 gauge or switch to a Low Tension EverTune module for optimized performance.
How to Use This evertune calculator
- Enter your guitar’s Scale Length. This is usually 25.5″ for Fenders and 24.75″ for Gibsons.
- Select the String Gauge you intend to use. Our evertune calculator includes standard thicknesses for various string materials.
- Choose your Target Pitch. This determines the frequency (Hz) used in the math.
- Review the Primary Result. If the tension is between 10-28 lbs, a Standard saddle is best.
- Check the Saddle Recommendation card to see which EverTune hardware module you need to purchase or install.
Key Factors That Affect evertune calculator Results
Several critical variables influence the final numbers generated by an evertune calculator:
- Scale Length: Longer scales increase tension significantly for the same pitch.
- String Mass: Thicker strings (higher gauge) have more mass and require more tension to reach a specific pitch.
- Target Frequency: Higher notes require exponentially more tension than lower notes.
- Material Density: Stainless steel strings have different unit weights than nickel-plated steel, affecting the evertune calculator output.
- Saddle Type: EverTune offers Standard, Low, and High tension springs; your calculated tension must match the spring rate.
- Tuning Stability: If your tension is too low (under 8 lbs), the EverTune system may not engage properly, leading to “Zone 1” issues.
Frequently Asked Questions (FAQ)
Most standard sets work, but you should always check an evertune calculator first to ensure the tension is between 10 and 28 lbs for standard saddles.
If tension exceeds 28 lbs on a standard saddle, you won’t be able to reach “Zone 2,” and the bridge will act like a fixed bridge. You would need a High Tension saddle.
The calculator assumes ideal conditions. While EverTune compensates for temperature, extreme heat can slightly alter string elasticity.
Yes, scale length is the distance from the nut to the bridge saddles. Multiscale guitars require calculating each string individually using the evertune calculator.
Pounds (lbs) is the industry standard for string tension in the US and UK, though many tools provide conversions.
Yes, though bass strings have much higher unit weights. The evertune calculator logic remains the same if you know the UW of the string.
Zone 2 is the ‘sweet spot’ where the bridge is actively balancing tension. Our evertune calculator ensures you land in this zone.
Often, yes. Heavy bottom strings at low pitches may require High Tension saddles, which you can verify using the evertune calculator.
Related Tools and Internal Resources
- guitar setup guide – A comprehensive guide to setting up your guitar for the first time.
- guitar string tension – View complete charts for all string brands and gauges.
- evertune installation – Step-by-step instructions for routing and installing the bridge.
- drop tuning tips – How to maintain clarity when tuning low.
- intonation guide – Perfect your guitar’s pitch accuracy across the fretboard.
- fretboard maintenance – Keep your neck in top shape for consistent tension.