Tonnes-force to Kilonewtons (tf to kN)

1 tonne-force equals 9.80665 kilonewtons exactly.

How to convert tonnes-force to kilonewtons

To convert tonnes-force to kilonewtons, multiply the number of tonnes-force by 9.80665. This factor is exact. To go the other way, multiply kilonewtons by 0.1019716213 (rounded).

kilonewtons = tonnes-force × 9.80665

Example: 10 tonnes-force = 98.0665 kilonewtons.

About these units

Tonne-force (tf)

CGS & old metricTraditional unit (still used in some regions)

Exactly 9,806.65 newtons, the weight of one metric tonne at standard gravity.

Heavy structures and presses call for a force unit scaled to match, and the tonne-force supplies it: the weight of one metric tonne, which is 1,000 kilograms-force. Other names for it are metric ton-force, megagram-force and megapond. Using exactly 9.80665 newtons per kilogram-force, it comes to 9,806.65 newtons, or about 9.8 kilonewtons.

Do not confuse it with the ton-force of US customary practice. NIST gives the short ton-force, based on 2,000 pounds-force, as 8,896.443 newtons, and the metric unit is about 10 percent larger. The tonne-force belongs to the same deprecated gravitational metric family as the kilogram-force and has no place in SI, where the kilonewton and meganewton are used instead. NIST tables have no entry for the metric version, so its value here comes from the kilogram-force definition.

1 tonne-force = 9,806.65 newtons (exactly).

Sources: Wikipedia: Kilogram-force; NIST SP 811, Appendix B.8 conversion factors

Kilonewton (kN)

Metric (SI)Current unit

1,000 newtons. Used for structural loads, climbing gear ratings and engine thrust.

Kilonewtons exist because the newton is small. The prefix kilo- dates to the 1795 French decimal system and means one thousand, and attaching it to the newton, which the CGPM named in 1948, gives a unit sized for the loads that engineers actually handle. A kilonewton is 1,000 newtons.

One kilonewton is the weight of roughly 102 kilograms at standard gravity, or about 510 of the 200-gram apples that make a handy picture of a single newton. Structural engineers quote building and bridge loads this way, and rocket and jet engine makers quote thrust in kilonewtons and meganewtons. Each Space Shuttle solid rocket booster produced 3,300,000 pounds-force, or 14.7 meganewtons, which is 14,700 kilonewtons. Strengths of ropes, anchors and climbing hardware are also commonly given in the unit.

1 kilonewton = 1,000 newtons (exactly).

Sources: Wikipedia: Newton (unit); Wikipedia: Metric prefix; Wikipedia: Pound (force)

Related conversions

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