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CD Calculator

3-Month CD Calculator

See what 90 days in a CD actually earns.

À l'échéance
25 264,52 $US
Intérêts
264,52 $US
Votre CD
$
%

Le taux est exprimé en

m

3 mois

Durées courantes

Fréquence de capitalisation

Valeur à l'échéance
25 264,52 $US
Intérêts totaux gagnés
264,52 $US
APY effectif
4,30%

25 000,00 $US dans un CD sur 3 mois à 4,30% APY, capitalisé quotidienne, atteint 25 264,52 $US — soit 264,52 $US d’intérêts, en moyenne 88,17 $US par mois.

Solde sur la durée

CapitalIntérêts
Afficher les chiffres sous forme de tableau
Solde sur la durée
MoisCapitalIntérêtsSolde
À l’ouverture25 000,00 $US0,00 $US25 000,00 $US
1mo25 000,00 $US87,86 $US25 087,86 $US
2mo25 000,00 $US176,04 $US25 176,04 $US
3mo25 000,00 $US264,52 $US25 264,52 $US

Calculated in your browser using A = P(1 + r/n)nt. Nothing is sent to a server. Figures are before tax; confirm exact terms with your bank.

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Formules et contenu vérifiés pour la dernière fois le . Les taux bancaires évoluent fréquemment — confirmez les taux en vigueur directement auprès de votre établissement.

La réponse en bref

How much does a 3-month CD earn?

A 3-month CD holds your deposit for about 90 days and pays a fixed rate for that period, after which it matures or renews. On a $25,000 deposit at 4.30% APY the term earns $264.52 and matures at $25,264.52; on $10,000 it earns $105.81. Because the term is short, two things follow that do not apply to longer CDs. First, the interest is small enough that a high-yield savings account paying within about 0.30% of the CD rate will usually leave you better off, since it keeps the money liquid for nothing. Second, the early withdrawal penalty — commonly 90 days of interest, which on a 90-day CD is all of it — can consume the entire return and, at many banks, dip into principal. A 3-month CD is therefore worth opening when the rate clearly beats savings and you are certain of the date you need the money back.

Formule et méthode

Comment le calcul est effectué

A = P(1 + r/n)^(nt), t = 0.25

The standard compound growth formula with a quarter-year term. Three months is 0.25 years, or 91 days on a daily-compounding basis.

A
Maturity value after roughly 90 days
P
Opening deposit
r
Nominal annual rate as a decimal
n
Compounding periods per year (daily = 365)
t
0.25 — the term expressed in years

Étape par étape

  1. 1

    Convert the advertised rate to a decimal and divide by n.

  2. 2

    Raise (1 + r/n) to the power of n × 0.25 — roughly 91 daily credits.

  3. 3

    Multiply by the deposit for the 90-day maturity value.

  4. 4

    Subtract the deposit to isolate the interest the quarter earned.

  5. 5

    Compare that figure against three months of high-yield savings interest before committing.

Mode d'emploi

Comment utiliser ce calculateur

Quatre données, des résultats en direct. Rien à valider et aucune inscription.
  1. 1

    Enter the deposit

    Type the amount you plan to place for the quarter. Short promotional CDs often carry a higher minimum than the bank's standard terms.

  2. 2

    Enter the 3-month rate

    Use the rate quoted specifically for the 3-month term, not the bank's headline rate — the headline usually belongs to a different, longer term.

  3. 3

    Read the interest, not the balance

    On 90 days the maturity value looks almost unchanged. The interest figure is the number that tells you whether the term was worth it.

  4. 4

    Compare against staying liquid

    Check the same deposit for three months in a high-yield savings account. If the gap is small, the CD is buying you very little for the loss of access.

Exemples

Exemples chiffrés

Des chiffres réels, calculés de bout en bout — pour que vous puissiez vérifier le calculateur avec vos propres montants.

A $25,000 emergency reserve parked for one quarter

Données saisies

Deposit
$25,000
Rate
4.30% APY
Term
3 months

Résultat

Interest earned
$264.52
Maturity value
$25,264.52

A quarter at 4.30% returns $264.52. A high-yield savings account at 4.00% over the same 90 days would pay $246.34 and keep the money available — so the CD is buying $18.18 of extra return in exchange for locking up $25,000. That is a thin trade.

The same CD broken at day 45, with a 90-day interest penalty

Données saisies

Deposit
$25,000
Rate
4.30% APY
Withdrawn
Day 45 of 90
Penalty
90 days of interest

Résultat

Interest earned by day 45
$130.10
Penalty charged
$265.07
Shortfall taken from principal
$134.97

On a 3-month CD a 90-day penalty is larger than the interest the CD can possibly have earned before maturity. Federal rules permit the bank to take the difference out of principal, so breaking a short CD early can return less than you deposited. This is the defining risk of the term.

Méthodologie

Exactitude et hypothèses

Tout calculateur repose sur des hypothèses. Voici les nôtres, énoncées clairement, pour que vous sachiez exactement ce que les chiffres prennent en compte et ce qu'ils ignorent.
  • Three months is treated as 0.25 years. Banks count actual days, so a 91- or 92-day quarter pays marginally more than shown.

  • The rate is fixed for the term and interest is retained rather than paid out.

  • The comparison against savings assumes the savings rate holds for the full quarter. Savings rates are variable and can be cut at any time — that is the one advantage the CD has here.

  • Penalty figures use a 90-day-interest convention. Some banks charge one month of interest on short terms, others all interest earned; the disclosure states which.

Les conventions suivent la Regulation DD (12 CFR 1030), qui encadre la façon dont les établissements américains communiquent l'APY des comptes de dépôt. Les dépôts effectués auprès d'établissements assurés sont protégés par la FDIC jusqu'à $250,000 par déposant, par banque et par catégorie de propriété.

Sources primaires

D'où viennent ces règles

Les conventions que suit ce calculateur sont fixées par les régulateurs, pas par nous. Chacune renvoie à l'organisme émetteur afin que vous puissiez la vérifier plutôt que de nous croire sur parole.

Détails

Points clés et règles à connaître

Des faits à parcourir rapidement, à connaître avant d'ouvrir ou de renouveler un CD.
  • A 90-day interest penalty on a 90-day CD means there is no window in which early withdrawal leaves you ahead. Regulation DD lets institutions take the shortfall from principal, and most reserve the right to.

  • 3-month CDs almost never carry the bank's best rate. Promotional pricing clusters at 6, 7, 11 and 13 months, because those are the terms banks use to attract deposits.

  • The term auto-renews unless you act. A 3-month CD renewing four times a year gives you four short grace periods to miss — set a calendar reminder for the maturity date the day you open it.

  • Because the term is under a year, the quoted APY is an annualised figure you will not actually receive. Earning 4.30% APY for three months yields about 1.06% of the deposit, not 4.30%.

  • Treasury bills at 13 weeks are the direct competitor. They are exempt from state and local income tax, which in a high-tax state can beat a nominally higher CD rate.

Cas d'usage

À qui s'adresse ce calculateur

  • Savers with a known 90-day horizon

    Money earmarked for a tax bill, a tuition instalment or a closing date in three months. The date is fixed, so the lock-up costs nothing and the rate is guaranteed.

  • Rate watchers waiting to commit

    If you expect rates to move soon, a 3-month CD holds a floor while keeping you three months from a decision — the shortest lock a CD offers.

  • Anyone comparing against savings

    The honest use of this page is often to talk yourself out of the CD. Run both numbers; on a short term the gap is frequently too small to justify the loss of access.

FAQ

FAQ — 3-Month CD Calculator

Des réponses directes aux questions les plus posées sur ce calcul. Pour aller plus loin, consultez la FAQ générale.
  • About a quarter of the annual rate. At 4.30% APY a $25,000 deposit earns $264.52 over three months and $10,000 earns $105.81. The APY is annualised, so a three-month term delivers roughly 1.06% of the deposit rather than 4.30%.

Sécurité et confidentialité

Vos chiffres ne quittent jamais votre navigateur

Chaque calcul de ce site s'exécute en JavaScript sur votre propre appareil. Il n'y a ni compte, ni appel serveur, ni mesure d'audience associée aux chiffres que vous saisissez.
  • Formules aux normes bancaires

    Utilise les mêmes conventions d'intérêts composés et d'APY que les banques soumises à la Regulation DD.

  • 100 % gratuit, sans connexion

    Aucune inscription, aucun mur d'e-mail, aucun paywall. Chaque calculateur est pleinement utilisable dès la première visite.

  • Vos données ne quittent jamais votre navigateur

    Chaque calcul s'exécute côté client en JavaScript. Rien n'est envoyé à un serveur ni conservé.

Diffusé en HTTPS, sans contenu mixte. Lisez notre politique de confidentialité ou consultez les formules et la méthodologie qui sous-tendent chaque chiffre.

Is 90 days worth locking up?

Run your own deposit and compare the quarter's interest against leaving the money liquid.