I-Calculator yesayizi yesampula
Thola ubukhulu besampula ye-survey ye-target margin of error.
Iziphetho zivuselelwa uma ubhala.
Malunga nale khadi
This sample size calculator finds how many people you need to survey for a chosen margin of error and confidence level — the planning step before you run a poll or study. It uses the standard formula n = z²·p(1 − p) / e², where z is the critical value for the confidence level, p the expected proportion and e the target margin of error as a decimal.
When you supply a total population size it also applies a finite-population correction, n = n₀ / (1 + (n₀ − 1)/N), which lowers the required sample when you are surveying a large fraction of a small group. A table shows the sample needed at several common margins of error, and the result is always rounded up because you cannot survey a fraction of a person.
Worked example: for a 5% margin at 95% confidence with an unknown proportion (p = 0.5), n = 1.96² × 0.5 × 0.5 ÷ 0.05² = 3.8416 × 0.25 ÷ 0.0025 ≈ 384.16, so you need 385 respondents. Tightening the margin to 3% pushes that to about 1,068. The default 50% proportion gives the largest, safest sample; entering a better estimate of the true proportion reduces it.
Imibuzo ebuzwa kaningi
Ubukhulu besampula bucalwa kanjani?
Ifomula eyinhloko yi n = z²·p(1 − p) / e², lapho i-z iyisibalo esibalulekile sokuzithemba, p isibalo esilindelekile futhi e isibalo esincane sephutha njengezinga leshumi. Imiphumela iqoqwe ngoba awukwazi ukubheka inhlanganisela yomntu.
Yini iphutha lomphakathi ophele?
Uma inani lakho lincane, udinga izimpendulo ezincane kunale fomula eyinhloko ephakamisa. Ukuxazulula n = n₀ / (1 + (n₀ − 1)/N) kuncane isampula ebheke ubukhulu beqembu N. Kubalulekile kakhulu uma isampula iyisiqephu esikhulu sengxenye egcwele.
Ingabe abantu abaningi ngifuna ukuwathola ku-95% izinga lokuzithemba?
Kuxhomekeka kunoma yikuphi ukufinyelela kwephutha ongakwenzi. Ku-95% uqiniseko nge-5% ukufinyelela futhi akukho ukulinganiselwa okungaphambili odinga mayelana 385 abaphenduli; 3% ukufinyelela odinga mayelana 1,068 no-1% ukufinyelela mayelana 9,604.
Kungani isilinganisi sincane?
Awukwazi ukubheka ingxenye yomuntu, ngakho noma yisiphi isenzo esihlukanisiwe sizojikeleza kuze kube yinombolo elandelayo egcwele. Ukujikeleza phezulu ngaphezu kokuhla kuqinisekiswa ukuthi ibanga lephutha alikhulu kunalokho ofuna ukulifinyelela.
Ingabe kufanele ngishiye ubukhulu beqembu eliphilayo olungasebenzi?
Uzoshiya ku zero (noma ungenalo) uma inani likhulu kakhulu noma aliziwa, elinikeza ubukhulu besampula olujwayelekile "lomphakathi ongenalutho". Faka inani elingokoqobo kuphela uma lincane ngokwanele ukuthi ukulungisa kuncane kakhulu.
Ngingayinciphisa kanjani isampula edingekayo?
Yamkela ibanga elikhulu lephutha, sebenzisa izinga eliphansi lokuzithemba, noma nikeza inhlanganisela engaphezulu kwe-50% uma unesibalo esithembekile. Yonke le misebenzi ikhuphula inani lemiphumela efuna ifomula.
API — sebenzisa le calculator kusuka kukhodi
Nquma le calculator njenge JSON evulekile yendawo yokuqeda - akukho isithonjana esidingekayo. Thumela amaxabiso endawo ngezansi njengezilungiselelo zombuzo noma i-JSON. Noma yini ongayishiya isebenzisa iphutha elifanayo elifakwe ngaphambili lekhasi; ipharamitha engaziwa yi-400, ayikho i-zero emnyama. Funda i-API egcwele →
Ingxenye yendawo
GET https://calculator.free/api/v1/sample-size/curl
curl "https://calculator.free/api/v1/sample-size/?conf=1.96&e=5"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/sample-size/?" + new URLSearchParams({
"conf": "1.96",
"e": "5"
}));
const data = await r.json();
console.log(data.results);Izibalo ziyisilinganiso esisetshenziswa ukuqondisa kuphela, hhayi ukucebisa ngezimali, ukwelashwa noma ukukhokha.