diff --git a/include/psa/crypto_sizes.h b/include/psa/crypto_sizes.h
index f6373b8..4dc8ad4 100644
--- a/include/psa/crypto_sizes.h
+++ b/include/psa/crypto_sizes.h
@@ -657,4 +657,91 @@
      PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \
      0)
 
+/** The default nonce size for an AEAD algorithm, in bytes.
+ *
+ * This macro can be used to allocate a buffer of sufficient size to
+ * store the nonce output from #psa_aead_generate_nonce().
+ *
+ * See also #PSA_AEAD_NONCE_MAX_SIZE.
+ *
+ * \note This is not the maximum size of nonce supported as input to #psa_aead_set_nonce(),
+ *       #psa_aead_encrypt() or #psa_aead_decrypt(), just the default size that is generated by
+ *       #psa_aead_generate_nonce().
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ *          zero times, so you should not pass arguments that contain
+ *          side effects.
+ *
+ * \param key_type  A symmetric key type that is compatible with algorithm \p alg.
+ *
+ * \param alg       An AEAD algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_AEAD(\p alg) is true).
+ *
+ * \return The default nonce size for the specified key type and algorithm.
+ *         If the key type or AEAD algorithm is not recognized,
+ *         or the parameters are incompatible, return 0.
+ *         An implementation can return either 0 or a correct size for a key type
+ *         and AEAD algorithm that it recognizes, but does not support.
+ */
+#define PSA_AEAD_NONCE_LENGTH(key_type, alg) \
+    (PSA_BLOCK_CIPHER_BLOCK_SIZE(key_type) == 16 && \
+         (PSA_ALG_AEAD_WITH_DEFAULT_TAG_LENGTH(alg) == PSA_ALG_CCM || \
+          PSA_ALG_AEAD_WITH_DEFAULT_TAG_LENGTH(alg) == PSA_ALG_GCM) ? 12 : \
+     (key_type) == PSA_KEY_TYPE_CHACHA20 && \
+          PSA_ALG_AEAD_WITH_DEFAULT_TAG_LENGTH(alg) == PSA_ALG_CHACHA20_POLY1305 ? 12 : \
+     0)
+
+/** The maximum default nonce size among all supported pairs of key types and AEAD algorithms, in bytes.
+ *
+ * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() may return.
+ *
+ * \note This is not the maximum size of nonce supported as input to #psa_aead_set_nonce(),
+ *       #psa_aead_encrypt() or #psa_aead_decrypt(), just the largest size that may be generated by
+ *       #psa_aead_generate_nonce().
+ */
+#define PSA_AEAD_NONCE_MAX_SIZE 12
+
+/** The default IV size for a cipher algorithm, in bytes.
+ *
+ * The IV that is generated as part of a call to #psa_cipher_encrypt() is always
+ * the default IV length for the algorithm.
+ *
+ * This macro can be used to allocate a buffer of sufficient size to
+ * store the IV output from #psa_cipher_generate_iv() when using
+ * a multi-part cipher operation.
+ *
+ * See also #PSA_CIPHER_IV_MAX_SIZE.
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ *          zero times, so you should not pass arguments that contain
+ *          side effects.
+ *
+ * \param key_type  A symmetric key type that is compatible with algorithm \p alg.
+ *
+ * \param alg       A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true).
+ *
+ * \return The default IV size for the specified key type and algorithm.
+ *         If the algorithm does not use an IV, return 0.
+ *         If the key type or cipher algorithm is not recognized,
+ *         or the parameters are incompatible, return 0.
+ *         An implementation can return either 0 or a correct size for a key type
+ *         and cipher algorithm that it recognizes, but does not support.
+ */
+#define PSA_CIPHER_IV_LENGTH(key_type, alg) \
+    (PSA_BLOCK_CIPHER_BLOCK_SIZE(key_type) > 1 && \
+        ((alg) == PSA_ALG_CTR || \
+         (alg) == PSA_ALG_CFB || \
+         (alg) == PSA_ALG_OFB || \
+         (alg) == PSA_ALG_XTS || \
+         (alg) == PSA_ALG_CBC_NO_PADDING || \
+         (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_SIZE(key_type) : \
+     (key_type) == PSA_KEY_TYPE_CHACHA20 && \
+         (alg) == PSA_ALG_CHACHA20 ? 12 : \
+     0)
+
+/** The maximum IV size for all supported cipher algorithms, in bytes.
+ *
+ * See also #PSA_CIPHER_IV_LENGTH().
+ */
+#define PSA_CIPHER_IV_MAX_SIZE 16
+
 #endif /* PSA_CRYPTO_SIZES_H */