| 782 | A Guide To Reading and Writing Japanese (Florence Sakade) |
| 697 | A Guide To Reading and Writing Japanese 3rd edition (Henshall, Seeley and De Groot) |
| 671 | A Guide To Remembering Japanese Characters (Kenneth G. Henshall) |
| 515 | A New Dictionary of Kanji Usage |
| 722 | Classic Nelson (Andrew Nelson) |
| 623 | Essential Kanji (P.G. O’Neill) |
| 370 | Japanese Kanji Flashcards (Max Hodges and Tomoko Okazaki) |
| 653 | Japanese Names (P.G. O’Neill) |
| 816 | Kanji and Kana (Spahn and Hadamitzky) |
| 835 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 501 | Kanji in Context (Nishiguchi and Kono) |
| 216 | Kodansha Compact Kanji Guide |
| 1617 | Kodansha Kanji Dictionary (Jack Halpern) |
| 849 | Kodansha Kanji Learner’s Dictionary (Jack Halpern) |
| 1164 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 1284 | Les Kanjis dans la tete (Yves Maniette) |
| 2334 | Morohashi |
| 1265 | New Japanese English Character Dictionary (Jack Halpern) |
| 535 | New Nelson (John Haig) |
| 1276 | Remembering The Kanji (James Heisig) |
| 1369 | Remembering The Kanji, 6th edition (James Heisig) |
| 682 | Tuttle Kanji Cards (Alexander Kask) |
Jōyō kanji, taught in grade 5
JLPT level N2
538 of 2500 most used kanji in newspapers
Stroke order
On reading compounds
- 効 【コウ】 efficacy, benefit, efficiency, effect, result, success
- 効果 【コウカ】 effect, effectiveness, efficacy, result, effects (e.g. sound effects, visual effects, special effects)
- 実効 【ジッコウ】 practical effect, efficacy, efficiency
- 時効 【ジコウ】 statute of limitations, lapse of rights after a period of time, prescription (including acquisitive and extinctive prescription), becoming invalid or void after a set time, ageing, aging
Kun reading compounds
- 効く 【きく】 to be effective, to take effect, to be good (for), to work, to function well, to be possible (to do, use, etc.), to be able to, to taste (alcohol), to try
- 効き目 【ききめ】 effect, virtue, efficacy, impression, one's dominant eye
Readings
- Korean:
- hyo
Spanish
- eficacia
- eficiencia
- efecto
- ser efectivo
Portuguese
- mérito
- eficácia
- eficiência
- benefício
French
- efficacité
- bénéfique
- mérite
| 445 | 2001 Kanji |
| 2g6.2 | The Kanji Dictionary |
| 1-6-2 | SKIP code |
| 0442.7 | Four corner code |
| 1-24-90 | JIS X 0208-1997 kuten code |
| 52b9 | Unicode hex code |