Load Inertia / Motor Inertia → Recommended <5:1 for high performance, <10:1 typical

T_rms = √[(T1² t1 + T2² t2 + ... ) / T_cycle]

Servo Motor Load Calculator

Calculate required servo torque, inertia ratio, acceleration time and sizing for rotary and linear loads. RMS and peak torque with motion profile.

RMS Torque

1.2 Nm

Load 5kg • Radius 0.1m • Accel 2 rad/s²

Servo Sizing & Load

Featured: Torque • Inertia • Accel • RMS

Load Type

Load Mass m (kg)

Radius r (m)

Acceleration α (rad/s²)

Friction Torque Tf (Nm)

Motor Inertia Jm (kg·m²)

Cycle Time t_cycle (s)

Torque vs Acceleration

Required torque profile

Key Formulas

Inertia J = m r² / 2 (rotary) or m (lead/2π)² (linear)
Accel Torque Ta = J α
RMS Torque = √[(Ta² t_a + T_f² t_c + 0 t_d) / t_cycle]
Inertia Ratio = J_load / J_motor

Enter load details to calculate

Servo Sizing Guidelines

Inertia Ratio

High precision: <5:1

Standard: <10:1

Max typical: 20:1 with tuning

Torque Margin

Peak Torque: <200% motor rated

RMS Torque: <80% rated

Add 20–50% safety