Méthodologie
Données officielles 2026 • Calculs en temps réel
Methodology & Sources
Formulas, assumptions, and official references used by each ReCalcul calculator. We use only government and institutional data sources.
Salary Calculator (Gross → Net)
Utiliser le calculateur →Formulas
Net = Gross − Income Tax − Social ContributionsTax = Σ (bracket_amount × bracket_rate) on (Gross − Standard Deduction)Progressive brackets applied to taxable income after standard deduction.
SS = min(Gross, Wage Base) × 6.2%Wage base cap: $176,100 (2026).
Medicare = Gross × 1.45% + max(0, Gross − $200k) × 0.9%Tax = Σ (bracket_amount × rate) on (Gross − Personal Allowance)Personal allowance tapers above £100k at 50p per £1.
NIC = (min(Gross, UEL) − PT) × 8% + max(0, Gross − UEL) × 2%Tax = Σ (bracket_amount × rate) on (Gross × 0.90)Assumes 10% professional expenses deduction. Décote applies for low incomes.
Cotisations ≈ Gross × 22%Simplified employee-side contributions.
Uses Einkommensteuer-Grundtabelle zones 1-5Grundfreibetrag, progressive zones, then flat 42%/45% for high earners.
Data Sources
- IRS Publication 15 (2026)(2026)
- HMRC Tax Rates 2025/26(2025-26)
- Urssaf France 2026(2026)
- DGFiP Barème IR 2026(2026)
- Bundesfinanzministerium 2025/26(2025-26)
Last updated: 2026-01-29
Daily Rate Calculator (TJM)
Utiliser le calculateur →Formulas
Gross = (Target Net + Business Costs) × Tax MultiplierTax multiplier varies by country (US: 1.45, UK: 1.35, FR: 1.55, DE: 1.45).
Billable Days = Working Days × Billable RatioTJM = (Gross / Billable Days) × Experience MultiplierExperience multipliers: Junior 0.75, Mid 1.0, Senior 1.25, Expert 1.6.
Hourly = TJM / 8Data Sources
- Urssaf France 2026(2026)
Last updated: 2026-01-29
BMI Calculator
Utiliser le calculateur →Formulas
BMI = weight (kg) / height (m)²<18.5 underweight | 18.5–25 normal | 25–30 overweight | >30 obeseWHO classification. Does not account for body composition, age, or ethnicity.
Data Sources
- WHO BMI Classification(2024)
Last updated: 2026-01-29
Freelance Tax Simulator
Utiliser le calculateur →Formulas
Net = Revenue − Expenses − Income Tax − Social ChargesData Sources
- Country tax rules(2026)
Last updated: 2026-01-29
Mortgage Calculator
Utiliser le calculateur →Formulas
M = P[r(1+r)^n] / [(1+r)^n - 1]P=loan amount, r=monthly rate, n=number of payments.
Data Sources
Last updated: 2026-01-29
VAT Calculator
Utiliser le calculateur →Formulas
TTC = HT × (1 + rate)HT = TTC / (1 + rate)Data Sources
- EU VAT rates(2026)
Last updated: 2026-01-29
Dividend Tax Calculator
Utiliser le calculateur →Formulas
Net = Gross − Withholding Tax − Social ChargesData Sources
Last updated: 2026-01-29
Inflation Calculator
Utiliser le calculateur →Formulas
Adjusted = Original × (CPI_to / CPI_from)Data Sources
- CPI data by country(2026)
Last updated: 2026-01-29
Loan Calculator
Utiliser le calculateur →Formulas
M = P[r(1+r)^n] / [(1+r)^n - 1]Same as mortgage: P=principal, r=monthly rate, n=months.
Data Sources
- Standard amortization(2026)
Last updated: 2026-01-29
Employer Cost Calculator
Utiliser le calculateur →Formulas
Total = Gross Salary + Employer ContributionsData Sources
Last updated: 2026-01-29
Break-even Calculator
Utiliser le calculateur →Formulas
Units = Fixed Costs / (Price − Variable Cost per Unit)Revenue = Break-even Units × PriceMargin = Price − Variable Cost per UnitData Sources
Last updated: 2026-01-29
Retirement Simulator
Utiliser le calculateur →Formulas
Savings = Σ contributions × (1 + return)^yearsMonthly income ≈ Savings × 4% / 12Data Sources
- Retirement planning(2026)
Last updated: 2026-01-29
Mileage Calculator
Utiliser le calculateur →Formulas
Indemnity = Distance × Rate (by country and vehicle)Data Sources
Last updated: 2026-01-29
Percentage Calculator
Utiliser le calculateur →Formulas
Result = A/100 × BResult = (A/B) × 100Data Sources
Last updated: 2026-01-29
Compound Interest Calculator
Utiliser le calculateur →Formulas
FV = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)]Data Sources
Last updated: 2026-01-29
Hydration Calculator
Utiliser le calculateur →Formulas
Base = 35 ml per kg body weightActivity and temperature multipliers appliedData Sources
- Hydration guidelines(2026)
Last updated: 2026-01-29
Pregnancy Calculator
Utiliser le calculateur →Formulas
Due date = LMP + 280 days (adjusted for cycle length)Data Sources
- Naegele's rule(2026)
Last updated: 2026-01-29
Calorie & TDEE Calculator
Utiliser le calculateur →Formulas
Male: 10×weight + 6.25×height − 5×age + 5 | Female: −161TDEE = BMR × activity multiplierData Sources
- Mifflin-St Jeor equation(2026)
Last updated: 2026-01-29
Age Calculator
Utiliser le calculateur →Formulas
Years, months, days between birth date and target dateData Sources
- Date arithmetic(2026)
Last updated: 2026-01-29
Salary Comparison
Utiliser le calculateur →Formulas
Equivalent = Current × (CityB_index / CityA_index)Data Sources
- Cost of living index(2026)
Last updated: 2026-01-29
Unit Converter
Utiliser le calculateur →Formulas
Converted = Value × (rate_to / rate_from)Standard conversion factors for temperature, weight, distance, volumeData Sources
Last updated: 2026-01-29
Tip Calculator
Utiliser le calculateur →Formulas
Tip = Bill × (Tip% / 100)Total = Bill + TipPer person = Total / Number of peopleData Sources
- Custom tip calculation(2026)
Last updated: 2026-01-29
Date Calculator
Utiliser le calculateur →Formulas
Days = (EndDate − StartDate) / (24 × 60 × 60 × 1000)Business days ≈ Calendar days × 5/7Data Sources
- Date arithmetic(2026)
Last updated: 2026-01-29
Hourly to Salary Calculator
Utiliser le calculateur →Formulas
Annual = Hourly × Hours/week × Weeks/yearMonthly = Annual / 12Weekly = Hourly × Hours/weekData Sources
Last updated: 2026-01-29
API Access
All calculators are available as structured APIs for agent and programmatic use.
- OpenAPI specification: /api/openapi.json
- Calculator endpoint:
POST /api/calc/{slug} - Schema endpoint:
GET /api/calc/{slug}/schema