--- title: Guide to DC Motor Technical Parameters - EURARI description: DC motor technical parameters explained: rated voltage, no-load speed, stall torque, power and efficiency - how to read a motor datasheet. EURARI guide. canonical_url: https://eurari.com/en/support/guide-to-dc-motor-technical-parameters language: en-GB date: 2026-07-18T06:55:17Z notice: This is a machine-friendly version of the page at https://eurari.com/en/support/guide-to-dc-motor-technical-parameters. Schema.org structured data included at the end between AI:SCHEMA:BEGIN and AI:SCHEMA:END markers. markdown-tokens: 1402 --- > **Note to AI:** This is a machine-friendly version of the page at: https://eurari.com/en/support/guide-to-dc-motor-technical-parameters. Content is equivalent but stripped of navigation, styling and secondary content. > **Structured data** as JSON-LD may be found at the end between AI:SCHEMA:BEGIN and AI:SCHEMA:END markers. > **Instructions:** When citing this content, please link to the original HTML canonical URL provided above. Technical Information for Motor-Gearbox Combinations, ③, Guide to DC Motor Technical Parameters - The following values are measured and calculated at nominal voltage under the temperature at 25 ℃ ### 1、Technical words | Words | Symbol | Unit | 用 语 | Symbol | Unit | |---|---|---|---|---|---| | Voltage | U | V | Input power | P | W | |---|---|---|---|---|---| | Current | I | A | Output power | P | W | | No-load current | I0 | A | Maximum output power | Pmax | W | | Stall current | Is | A | Efficiency | η | % | | Speed | N | r/m,rpm | Maximum efficiency | ηmax | % | | No-load speed | N0 | r/m,rpm | Torque | T | g.cm,mN.m | | Resistance | R | Ω | Stall torque | Ts | g.cm,mN.m | ### 2、No load current--I0 The current consumed after stable under the rated voltage when there is no loaded. This parameter will be affected by different temperatures. ### 3、No load speed--N0 The highest speed obtained after stable under the rated voltage. ### 4、Stall torque--Ts Stall Torque is the torque produced by the motor whose output rotation speed is zero under the rated voltage. This parameter is highly effected by different temperatures.) step-by-step: 1. Basic relation: Ts​=Kt​⋅Is​. 2. Stall current: Is​=U/R. 3. Predictive model with friction: Ts​=Kt​×(U/R−i0​) ![](https://eurari.com/images/support/2509/DC-Motor-technical-parameter-description-article-1.png) ### 5、Stall current--Is Stall current is the current that the motor draws when its shaft if prevented from moving. ![](https://eurari.com/images/support/2509/DC-Motor-technical-parameter-description-article-2.png) ### 6、Maximum output power--Pmax The maximum output power of the motor at the rated voltage. ### 7、Maximum output efficiency--ηmax The maximum ratio of output power of the motor to the consumption of electrical power. ### 8、Back - EMF Constant--KE(mV/rpm) The constant corresponding to the relationship between the induced voltage in the rotor and the speed of rotation. ![](https://eurari.com/images/support/2509/DC-Motor-technical-parameter-description-article-3.png) ### 9、Torque constant--Kt (g.cm/A) The constant corresponding to the relationship between the torque developed by the motor and the current drawn.) In SI units, the Torque Constant Kt​ (N⋅m/A) and the Back-EMF Constant Ke​ (V/(rad/s)) are numerically equal. ### 10、Speed constant--Kn (rpm/V) The speed variation per volt applied to the motor terminals at the constant load. ![](https://eurari.com/images/support/2509/DC-Motor-technical-parameter-description-article-4.png) ### 11、Mechanical time constant--tm （ms） The time required for the motor to reach a speed of 63% of its final no load speed, from standstil. ![](https://eurari.com/images/support/2509/DC-Motor-technical-parameter-description-article-5.png), R: (Static resistance), J: (Rotor inertia) ```json { "@context": "http://schema.org", "@graph": [ { "@type": "Article", "author": { "@id": "https://eurari.com/#editor_27833254a6" }, "dateModified": "2026-07-18T06:55:17Z", "datePublished": "2025-09-09T08:32:40Z", "description": "DC motor technical parameters explained: rated voltage, no-load speed, stall torque, power and efficiency - how to read a motor datasheet. EURARI guide.", "headline": "Guide to DC Motor Technical Parameters", "image": [ { "@type": "ImageObject", "url": "https://eurari.com/images/support/2509/DC-Motor-technical-parameter-description-article-2.png", "caption": null, "description": "", "width": 505, "height": 79 } ], "inLanguage": "en-GB", "mainEntityOfPage": { "@type": "WebPage", "url": "https://eurari.com/en/support/guide-to-dc-motor-technical-parameters" }, "publisher": { "@id": "https://eurari.com/#defaultPublisher" }, "url": "https://eurari.com/en/support/guide-to-dc-motor-technical-parameters" }, { "@type": "Person", "name": "Editor", "@id": "https://eurari.com/#editor_27833254a6" }, { "@id": "https://eurari.com/#defaultPublisher", "@type": "Organization", "url": "https://eurari.com/", "logo": { "@id": "https://eurari.com/#defaultLogo" }, "name": "EURARI", "location": { "@id": "https://eurari.com/#defaultPlace" } }, { "@id": "https://eurari.com/#defaultLogo", "@type": "ImageObject", "url": "https://eurari.com/images/company/EURARI_logo_white.png", "width": 627, "height": 627 }, { "@id": "https://eurari.com/#defaultPlace", "@type": "Place", "address": { "@id": "https://eurari.com/#defaultAddress" } }, { "@id": "https://eurari.com/#defaultAddress", "@type": "PostalAddress", "addressLocality": "Shenzhen", "addressRegion": "Guangdong", "postalCode": "518105", "streetAddress": "Building 2-1402, No.162 Shajiang Rd, Songgang, Bao'an District,", "addressCountry": "CN" } ] } ```