Inch-lbs to Nm converter

How to use the inch-pounds to newton-meters calculator

What this calculator does

This calculator converts torque between inch-pounds (in-lb) and newton-meters (N·m). It is useful when a fastener specification, torque wrench, service manual, drawing, or component datasheet uses a different unit from the tool in your hand. The conversion is an exact unit identity based on pound-force and inch definitions; it does not decide what torque a particular bolt, joint, plastic housing, electrical terminal, or mechanical assembly should receive. Always take the required setting from the equipment manufacturer or an approved engineering specification.

When to use it

Use the converter when translating a small-fastener specification from an imperial manual to an SI torque wrench, checking a bicycle or automotive service value, comparing electronics or aerospace assembly instructions, or preparing a unit-consistent worksheet for quality control. The NIST explanation of force units provides helpful background on the relationship between pound-force and the SI newton.

How to calculate

1. The calculator opens with a ready-to-use demonstration: 100 in-lb, equivalent to 11.2985 N·m. A validated Excel workbook is available immediately.
2. To convert imperial torque, replace the value in Inch-pounds (in-lb). The newton-meter field, result cards, nearby conversion table, and workbook model update live.
3. To work in the opposite direction, edit Newton-meters (N·m). The inch-pound value is recalculated from the same exact factor.
4. Select Download Excel to create a fresh .xlsx workbook from the current valid inputs. Select Reset to clear both data fields, results, table, and workbook state. Reset does not restore the demonstration and may disable the download until you enter a complete valid value again.

Input guide

Inch-pounds (in-lb) is a required finite decimal torque value expressed as pound-force inches. Enter plain digits with an optional leading minus sign and a period decimal separator, such as 100 or 22.5. Negative torque is accepted because direction can be represented by sign, although many tightening specifications are stated as positive magnitudes. A comma decimal such as “1,5,” scientific notation, unit text, and mixed symbols are rejected to prevent silent reinterpretation. Increasing this value increases the N·m result proportionally.

Newton-meters (N·m) is the bidirectional required field for SI torque. A realistic example is 10 N·m, which converts to about 88.5075 in-lb. It follows the same strict decimal format. Editing either field makes that field the source, so avoid trying to type into both simultaneously; the second field is always the computed equivalent. The International Bureau of Weights and Measures publishes the SI Brochure, which defines the coherent SI system containing the newton and meter.

Output guide

Converted torque is the primary exact unit conversion, displayed to a practical precision. Exact factor shows that one in-lb equals 0.1129848290276167 N·m. Foot-pounds divides inch-pounds by 12, providing a familiar secondary imperial comparison. The Nearby conversion table lists one-half, one, and two times the current torque; its columns are Multiplier, Inch-pounds, Newton-meters, and Foot-pounds. Zero means zero torque in every unit. A negative result preserves direction. Large values remain mathematically valid while still requiring appropriate tools and engineering judgment.

Worked example

For the startup value, multiply 100 in-lb by the exact factor: 100 × 0.1129848290276167 = 11.29848290276167 N·m. The main result rounds this to 11.2985 N·m. The secondary result is 100 ÷ 12 = 8.3333 ft-lb. Converting back divides 11.29848290276167 by the same factor and returns 100 in-lb within floating-point precision. The table then shows 50, 100, and 200 in-lb with matching SI and foot-pound values.